How to analyze whether a code entered in the text field is in the list of choices?

I am creating a form where after inserting a code in the text box, I want it to check if this code exists in the choices and if it does, release the next questions on the form to the respondent, otherwise, return a message that the code is invalid.

Welcome back to the community, @LAFS! Maybe this post discussed previously should help you solve your issue: