How to avoid default captcha alert?

Hello!

I use ajax form sending and just added captcha to my form.
If captcha isn't checked, I see double messages, one in alert and the same in my ajax pop-up.

I mean this thing:
https://github.com/getgrav/grav-plugin-form/blob/develop/templates/forms/fields/captcha/captcha.html.twig#L21-L26

How to disable it?

Start with templates/forms/fields/captcha/captcha.html.twig at lines 21-26, then inspect how the AJAX form displays validation messages. Confirm that an unchecked captcha currently produces both the browser alert and the AJAX pop-up, and define done as preventing the duplicate alert while retaining the captcha error.

Written by the indexing model from the issue text.