https://support.mozilla.org/en-US/kb/how-download-mozilla-vpn-your-desktop-or-mobile and https://support.mozilla.org/en-US/questions/new/mozilla-vpn for other KB articles. If you need further help then you can create a direct ticket at https://support.mozilla.org/en-US/questions/new/mozilla-vpn/form since Mozilla VPN is a subscription based product.

Hi, The Firefox built-in VPN is offered in stages to users in the US, UK, Germany and France (starting with [https://www.firefox.com/firefox/149.0/releasenotes/#:~:text=built-in%20VPN Firefox version 149]), and in Canada starting with [[Find what version of Firefox you are using|Firefox version]] 150. It may not be available to you yet, even if you’re in one of these locales, as the staged rollout takes time to reach everyone. If the built-in VPN is available, you would see a VPN icon in the top-right corner of the toolbar, which opens a prompt to turn on the VPN. You would also need to sign in to a Mozilla account. For more information, see the [[Use built-in VPN in Firefox]] article. If you wish, you can post your feedback about the Firefox built-in VPN to the [https://connect.mozilla.org/t5/discussions/introducing-firefox-s-built-in-vpn-ip-protection-now-in-the/td-p/120550 Mozilla Connect thread].

This thread was about the subscription based Mozilla VPN app https://www.mozilla.org/products/vpn/ as the built-in VPN feature did not start until later as of Firefox 149.0