Can’t add autocomplete attribute to forms

Hi,

I want to add an autocomplete="email" attribute to an <input type="email"> element in a subscription form.

When editing the form from the backend, I can add this element to the editable HTML a the form. But when I save the form, the autocomplete gets removed.

I’ve reproduced the issue on a blank WordPress 6.2 with only the SendInBlue plugin installed.