how to submit a form that was locked after being signed

I have created a fillable form and added a digital signature box. There is also a submit button on the form that sends the form back to me via e-mail once clicked. However, if someone were to lock the document after signing, then the submit button becomes useless. Is there a way to have the submit button still work after the document is locked? If not, is there a workaround for this? If someone puts their digital signature and doesn't click the lock document box, then the submit button still works as intended.