Install Kasm. (I have it running on a dedicated VM and followed the single server installation instructions: https://kasmweb.com/docs/latest/install/single_server_install.html)
Once installed, log into the Kasm host using the admin credentials and then configure the reverse proxy by going to Infrastructure > Zones in the left hand side panel and following the instructions here: https://kasmweb.com/docs/latest/how_to/reverse_proxy.html#update-zones
(Note: in my case, the default parameters worked fine)
Install the Cloudron App proxy and point it to your Kasm host e.g. https://[IP-ADDRESS]:443. Now you should be able to access the Kasm login page via the domain you set in the app proxy. e.g. kasm.yourdomain.tld
To use OpenID authentication, first we need to add Kasm as an OIDC client in Cloudron. Go to Cloudron > User Director > OpenID Connect Provider > New Client, and enter the following:
Name: kasm
Login callback URL: https://kasm.yourdomain.tld/api/oidc_callback
Signing Algorithm: RS256
Copy the resulting Client ID and Client Secret for use in step 5.
Now in Kasm, go to Access Management > Authentication > OpenID and follow the instructions here: https://kasmweb.com/docs/latest/guide/oidc.html
Main parameters to be set are:
Display Name: Can be anything e.g. Login with Cloudron
Hostname: kasm.yourdomain.tld
Client ID: paste from step 4
Client Secret: paste from step 4
Authorization URL: https://my.yourdomain.tld/openid/auth
Token URL: https://my.yourdomain.tld/openid/token
User Info URL: https://my.yourdomain.tld/openid/me
Scope (One Per Line): openid profile email
Username Attribute: sub
Redirect URL: this should be automatically populated and should match what you entered as the callback url in step 4 i.e. https://kasm.yourdomain.tld/api/oidc_callback
I believe that should be it! Give it a shot and let me know if you run into any issues. There could be a possibility that I forgot to document something in the above steps. Once it is confirmed to be working, I will polish it up and submit it as a community guide.