Max Submissions for Elementor Pro Form can be used when you want to limit the number of submissions to a form. Once the limit has been reached, the submit will fail with a custom error.

To use Max Submissions, you will need to refer to the ID of a counter field present in the same form.

You can also customize the error message to be displayed.

Another option to limit submissions is to use Conditional Validation. It's more complex, but you have the additional ability of hiding the submit button and of using more conditions at the same time.