How to add IAM conditions in gcp request for the TestIamPermissions API in golang?

Question

I'm trying to test permissions with the TestIamPermissions API provided by GCP, my permissions are scoped by IAM conditions, but as I see in gcp documentation, this API gets resource and TestIamPermissionsRequest as parameters,

This is how I use it for now in my code without the IAM conditions

var response *cloudresourcemanager.TestIamPermissionsResponse
            if err = apiRetryBackoff(func() error {
                response, err = c.projectsService.TestIamPermissions(check.projectID, &cloudresourcemanager.TestIamPermissionsRequest{Permissions: check.requiredPermissions}).Do()
                return err
            }); err != nil {
                return err
            }

And these are the documetations from gcp package code

// TestIamPermissions: Returns permissions that a caller has on the
// specified Project. For additional information about `resource` (e.g.
// my-project-id) structure and identification, see Resource Names
// (https://cloud.google.com/apis/design/resource_names). There are no
// permissions required for making this API call.
//
// - resource: REQUIRED: The resource for which the policy detail is
//   being requested. See the operation documentation for the
//   appropriate value for this field.
func (r *ProjectsService) TestIamPermissions(resource string, testiampermissionsrequest *TestIamPermissionsRequest) *ProjectsTestIamPermissionsCall {
    c := &ProjectsTestIamPermissionsCall{s: r.s, urlParams_: make(gensupport.URLParams)}
    c.resource = resource
    c.testiampermissionsrequest = testiampermissionsrequest
    return c
}

// TestIamPermissionsRequest: Request message for `TestIamPermissions`
// method.
type TestIamPermissionsRequest struct {
    // Permissions: The set of permissions to check for the `resource`.
    // Permissions with wildcards (such as '*' or 'storage.*') are not
    // allowed. For more information see IAM Overview
    // (https://cloud.google.com/iam/docs/overview#permissions).
    Permissions []string `json:"permissions,omitempty"`

    // ForceSendFields is a list of field names (e.g. "Permissions") to
    // unconditionally include in API requests. By default, fields with
    // empty or default values are omitted from API requests. However, any
    // non-pointer, non-interface field appearing in ForceSendFields will be
    // sent to the server regardless of whether the field is empty or not.
    // This may be used to include empty fields in Patch requests.
    ForceSendFields []string `json:"-"`

    // NullFields is a list of field names (e.g. "Permissions") to include
    // in API requests with the JSON null value. By default, fields with
    // empty values are omitted from API requests. However, any field with
    // an empty value appearing in NullFields will be sent to the server as
    // null. It is an error if a field in this list has a non-empty value.
    // This may be used to include null fields in Patch requests.
    NullFields []string `json:"-"`
}

I would be happy to get more explanation about how IAM gcp conditions can be tested ?

I tried to add the condition to the request with no success