Changing from required to NOT required

I have very limited knowledge in coding but our website developer created a referral form for us using coding. I have been trying for sometime to get a hold of them to no avail. As the form is already online and people are using it, is it a simple task of editing code to make a field in my form not required? I want them to be able to leave it blank and the form will still allow them to submit it. I would appreciate the help. Thanks

Depending. Can you share link to page where you insert form?

Just letting you know I sent you an email Tuanphan :)