Fairly easy to edit the code to remove the field from the required fields check, if you don’t mind editing the PHP file. All you need to do is to totally delete line 91 of the class-pta_sus_public.php file, the line that reads:
|| empty($_POST[‘signup_phone’])
That will make it not required.
To remove that field from the signup form, you need to remove the fields in two different locations further down in that same file. Signup form function starts on line 632 You’ll need to edit out the last paragraphs and text inputs on lines 682-685 and 705-708, making sure to leave the closing single quote and semicolon after the paragraph close tag in both locations.
That should work and shouldn’t mess up anything, although I haven’t tested it. Might want to save a backup copy of the file first. I did a quick look at where I save the signup into the database table, and it should still work without the phone field data.
Let me know if that works.