Enter URL for a ‘Submit’ button

I have a fillable PDF form on which I have placed a ’SUBMIT’ button. I want the button to send the form to my email address. With the button selected I open Form Properties. In the General tab I try to enter ‘mailto: myEmailAddress’ into the URL field but as soon as I type anything the field is automatically filled with the file path of the saved document. This can be deleted but not edited. I have switched off ‘URL recognition’ in the AutoCorrect dialogue but to no avail.
The technique seems to work without a hitch in the YouTube tutorial:

but not for me. Help would be appreciated.

MAC OS 11.7.4
Libreoffice version 7.1.0.3
No other save format apart from pdf

No help without some needed technical information: OS name, LO version and save format (besides the obvious PDF form). Ideally attach your Writer document so that we can experiment. For your own privacy, replace your real email address with “me@fake.mailer”.

Provide theis supplemental information by editing your question, not by using a comment. Thanks.