i developed a module to add two new fields in costumer address. The fields are showing but not saving in frontend checkout procedure. The fields are showing also in the admin area and there they saves correctly. Now, i don't know how to debug this. How can i check where the problem is in the frontend? Thank you.
EDIT
Ok, now i understand that my two custom attributes (codice_sdi and indirizzo_pec) are not saved in the shippingAddress javascript object. I've seen this using console.log. Any ideas?