Conditional API call resolved

This question was asked a long time ago but maybe someone is looking online for the solution like me today.
with contact form 7 I solved it using:
[select * mailuplist “Yes | 1” “No | 0”]
so in the integration of the api plugin I have inserted “list” next to “mailuplist”.
In this way if the user selects “yes” the id of the list is 1 (real list), if he selects “no” the id of the list is 0 (zero) which in this case is a list that does not exist: in this way the contact does not arrive on mailup