c# using aws AssumeRole for a given User that has MFA enabled - how to programmatically pass token does aws have a fixed token

Question

I am trying to use the AssumeRole for my account ,it is already set up but has MFA enabled So I need a way to send a token without having the user to enter it every time .

{
"Version": "2012-10-17",
"Statement": [
    {
        "Effect": "Allow",
        "Principal": {
            "AWS": "arn:aws:iam::123456789324:user/[email protected]"
        },
        "Action": "sts:AssumeRole",
        "Condition": {
            "Bool": {
                "aws:MultiFactorAuthPresent": "true"
            }
        }
    }
]

}

So how can I pass in the MFA token when making a call for the Assume Role

var client = new AmazonSecurityTokenServiceClient();

        string token = Console.ReadLine();  //--> Get from Authenticator App of your choice

        AssumeRoleRequest request = new()
        {
            RoleSessionName = "TestSesion",
            RoleArn = roleArn,
            DurationSeconds = 1600,
            TokenCode = token,
            SerialNumber = "arn:aws:iam::123456789324:user/[email protected]"
        };
        var assumeRoleResponse = await client.AssumeRoleAsync(request);

The SerialNumber is fixed but for the Token, how can this be set without the user having to put it in. When running an application in production is there a way to trust the initial user assuming the new role ?