Showing Internal 500 Error While submit form

Here is my site Read-Only:
(how to share your site Read-Only link)

Hi @webdevelopers_sp,

Welcome to the forum! Do you have reCAPTCHA enabled in Project Settings > Forms > reCAPTCHA?

If you have this enabled but haven’t added the reCAPTCHA element to your form you’ll have issues submitting your form.

Hope this helps!