Solved Email Optin Module is not saving my work

I am using email Optin Module with convertkit. Within this module, there is a section called FIELD. I unchecked the NAME field because I want it to show as FIRST NAME.
Now when I saved it and check it without the divi builder, the FIRST NAME has disappeared! How can I use the FIRST NAME field?

Thank you

ps
I clean out my clear on both my browser and Wordpress.