You’ll need to write something on your site that will provide the protocol discourse-connect protocol (which would mean that you didn’t have to develop anything in Discourse and it could work with discourse-core). Or, you could conceivably write a custom plugin in discourse that would authenticate against the wallet.
You can look at some of the other recently updated authentication plugins as a model. Discourse requires an email address, so you will need to provide something like username@mail.invalid to Discourse. I’m not entirely sure that works, but I recently saw someone post that they were doing that, so perhaps it does.
discourse.org mostly develops things for their enterprise users. If you have a budget for development, you can post in Marketplace .