How to add custom button to Joomla product card?

Question

PHP

Actually, that's the whole question) In the title.
How to add custom button to Joomla product card?
Please tell me, I was looking for something in /components/virtuemart/tmpl/
like it should have been there, I stick a button, the site goes to bed. Apparently not there or not,
tell me who knows and who is not too lazy.
Thanks in advance