Button with ‘mailto’ function to open a new email message window

Hi,

I’m working on this site: https://cartoonizr.com/

I’m not a big fan of filling in ‘contact forms’ I rarely do that myself. I rather like use the email client.

I want to create a button that, when clicked on, will open up the mailclient. In HTML it works through the ‘mailto’ functionality.

But if I add this to the button URL this doesn’t seem to be working.

How do I set this up properly?

Thank you