Free tool
Local business schema generator
Fill this in and you get the code that tells Google your address, phone number and opening hours. Paste it into your site and it is done. Nothing is sent anywhere. This runs in your browser.
Your code
Paste this into the head section of your website, or into whatever your site calls "custom code" or "header scripts".
While you are here
Want to know what else is missing?
Missing business markup is one of the commonest faults we find, and it is rarely the only one. The checker runs the rest in about ten seconds.