Invoke-RestMethod 'StatusCodeVariable' scope

Question

I have a .psm1 file that serves as a class with a number of methods for different REST requests. For the methods handling the REST requests, I am using splatting to pass in the 'Invoke-RestRequest' parameters. I am not able to access the 'StatusCodeVariable' key value for consumption within the local scope of the method. If I build the same request in the Integrated Powershell Console, I am able access the value of this parameter. Below is the code used in the Integrated Console. You can see that I am able to access the $errorCode value:

    $hashTable = @{
    >> Method = 'Get'
    >> Uri = 'https://blahblahblah'
    >> Credential = 'username'
    >> StatusCodeVariable = 'errorCode'
    >> }
    $newRequest = Invoke-RestMethod @hashTable -SkipHttpErrorCheck
    
    PowerShell credential request
    Enter your credentials.      
    Password for user username: ********
    
    $errorCode
    **200**

Within my class method handling the same request, the variable is not seen as defined in the method and I am therefore not able to use it for later consumption within the same scope, for example, if ($errorCode -eq '200') { do something }:

#### CLASS DEFINITION ####
     
class Dayforce {
    [object]$Headers
    [object]$Stopwatch
    [string]$Url
    [string]$Env
    [string]$Username 
    [string]$Password
    [string]$Token

    Dayforce() {
        # Environment variable
        $this.Env = 'test'
        # API credentials to be used by AccessToken() 
        $this.Username = 'user'
        $this.Password = 'password'
        $this.Headers = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
        # Instantiate [System.Diagnostics.Stopwatch] class
        $this.Stopwatch = [System.Diagnostics.Stopwatch]::new()
        # String placeholder for access token
        $this.Token = ""
        # Add 'Authorization' header to the Headers object, which will also pass the token string 
        $this.Headers.Add("Authorization", "Bearer " + $this.Token)
        # Default API URL for test environment
        $this.Url = 'https://someurl.com'
    }

    # This method will toggle between 'test' and 'prod' environments, along with changing URL, credentials and new token
    [void]ToggleEnvironment() {
        if ($this.Env -eq 'test') {
            $this.Url = 'https://produrl.com'
            $this.Env = 'prod'
            $this.Token = $this.AccessToken()
            $this.Headers.Authorization = 'Bearer ' + $this.Token
        }
        else {
            $this.Url = 'https://testurl.com'
            $this.Env = 'test'
            $this.Token = $this.AccessToken()
            $this.Headers.Authorization = 'Bearer ' + $this.Token
        }
        Write-Host "!! You are currently in the "$this.Env" environment !!"
    }

    ### GET REQUEST: EMPLOYEE DETAILS ###
    [object]EmployeeDetail(
        [string]$params
    ) { 
        # Check if more than 58 minutes has elapsed, and generate new access key if true
        if ($this.Stopwatch.Elapsed.minutes -gt 58) {
            $this.Stopwatch.Reset()
            $this.Token = $this.AccessToken()
            $this.Headers.Authorization = 'Bearer ' + $this.Token
        }
        $restParams = @{
            Method             = 'Get'
            Uri                = $this.Url + '/' + $params
            Headers            = $this.Headers
            MaximumRetryCount  = 5
            RetryIntervalSec   = 5  
            StatusCodeVariable = 'errorCode'
        }
        $newRequest = Invoke-RestMethod @restParams -SkipHttpErrorCheck
        if ($errorCode -ne '200') {
            Send-ErrorData($errorCode)
        }
        return $newRequest.Data
    }

    ### GET REQUEST: EMPLOYEE XREF CODES ###
    [object]EmployeeList(
        [string]$params
    ) {
        $restParams = @{
            Method             = 'Get'
            Uri                = $this.Url + '?' + $params 
            Headers            = $this.Headers  
            MaximumRetryCount  = 5
            RetryIntervalSec   = 5  
            StatusCodeVariable = 'errorCode'     
        }
        $newRequest = Invoke-RestMethod @restParams -SkipHttpErrorCheck 
        Write-Host 'Gathering employee xRefCodes from '$restParams.Uri 
        return $newRequest.Data
    }

    ### GET REQUEST: EMPLOYEE XREF CODES FOR TERMINATED EMPLOYEES BY DATE ###
    [object]TerminationList(
        [string]$date1,
        [string]$date2
    ) {
        $restParams = @{
            Method             = 'Get'
            Uri                = $this.Url + '?' + "filterTerminationStartDate=$date1&filterTerminationEndDate=$date2"
            Headers            = $this.Headers  
            MaximumRetryCount  = 5
            RetryIntervalSec   = 5  
            StatusCodeVariable = 'errorCode'    
        }
        $newRequest = Invoke-RestMethod @restParams -SkipHttpErrorCheck
        Write-Host 'Gathering employee xRefCodes from '$restParams.Uri 
        return $newRequest.Data
    }   

    ### POST REQUEST: REQUEST FOR ACCESS TOKEN ###
    [string]AccessToken() {
        if ($this.Env -eq 'test') {
            $tokenPath = 'https://testtoken.com/getToken'
        }
        else {
            $tokenPath = 'https://prodtoken.com/getToken'
        }
        $header = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
        $header.Add("Content-Type", "application/x-www-form-urlencoded")
        $restParams = @{
            Method             = 'Post'
            Uri                = $tokenPath
            Headers            = $header
            Body               = @{
                grant_type = 'password'
                companyId  = 'companyId'
                username   = $this.Username
                password   = $this.Password
                client_id  = 'client_id'
            }
            StatusCodeVariable = 'errorCode'  
        }
        $newToken = Invoke-RestMethod @restParams -SkipHttpErrorCheck
        $accessToken = $newToken.access_token
        $this.Stopwatch.Start()
        return $accessToken
    }
}

# Function to handle all http response codes that are not 200
function Send-ErrorData {
    param (
        [string]$errorCode
    )
    switch ($errorCode) {
        { $errorCode -eq 403 } { $message = 'This is a test'; Break }
    }
    Send-Pushover -Message "$message"
}
# Function to create a new instance of the Dayforce class
function New-Dayforce() {
    [Dayforce]::New()
}

# Class itself cannot be exported, so New-Dayforce() function exported
Export-ModuleMember -Function New-Dayforce

I would like to be able to pass $errorCode from within any of the REST request methods into Send-ErrorData(), and go from there with regard to the mobile notifications. In the EmployeeDetail() class method, I Included an example of how I would like to utilize the value stored in $errorCode, but as I said prior, am not able to, despite being in local scope.Thank you Mathias for suggesting that I place the entire class definition here for context, as well as your other suggestions which I will look into coding out! I appreciate all your feedback, thank you!