Formik input name is not an identifier

Question

In typescript-Formik form input are connected by names to variables. But what if a input is inserted by script, which name is not an Identifier. We have this problem with cloudflare Turnstile. There is a input inserted with the name "xxx-turnstile"

interface Values {
   firstName: string;
   lastName: string;
   email: string;
   xxx-turnstile: string; // syntax error
 }

how can I handle this? Thanks