Are you using #Conga Composer in an @* Experience Cloud * (aka Experience Site) build?  I'm happy to share my latest blog post about how to get this functionality set up and working.  There were lots of pitfalls but the results are incredible!  https://thedataarealright.blog/2023/05/26/how-to-configure-conga-composer-in-a-salesforce-experience-site/