We have a dual setup for our website, most of the site is served up on another CMS but the commerce side is all Magento 2. The primary CMS doesn't have any frontend logins for users but we need to provide login forms on that side of the site and login the user (in magento) and direct them over to the commerce side.
Is this possible with just a form on the other CMS and some key/token to pass? Or will this setup need to hit a script to login and connect with the API?
(I mostly speak from various reading and very little knowledge of Magento as I don't develop in it much at all)