I know there are tons of stack overflow pages out there that explain how to do this but everytime I take the code from here and put it in i get the same error and that error
It was this check that helped me since it was necessary for me to send a request to the API, and it was necessary to send nill instead of "" if the textField is without text.
textField.text!.count > 0 ? textField.text : nil
Alternatively, you can check this way (but this option did not fit me):
if textField.text != nil {
} else {
}