Get PasswordCredentialsToken with TOTP

[theexiile1305]

First of all this is a very great project.

In order to get a valid token you have to pass in username and admin like the following code snippet

// get a valid token from keycloak
    ctx := context.Background()
    token, err := config.PasswordCredentialsToken(ctx, "admin", "admin")
    if err != nil {
        panic(err)
    }

Unfortunately, I can't pass a required OTP-Token, so that my two factor authentication works. Can I adjust the PasswordCredentialsToken or add a second method, that I am able to pass the OTP-Token? The following code snippet describes my idea in detail

// get a valid token from keycloak
    ctx := context.Background()
    token, err := config.PasswordCredentialsToken(ctx, "admin", "admin", "123456")
    if err != nil {
        panic(err)
    }

The result would be another line totp=<one time token> within the application/x-www-form-urlencoded body