Reverse proxies are tricky.
I miss some information to give you the right answer (for instance, what the browser says about the missing resources or what is the LAMP behind your OJS?) but, in short, depending on your NPM and OJS/LAMP settings you will need different solutions but x-forwared-proto is the most efective I know. In apache you can set it as follows:
Set “SetEnvIf X-Forwarded-Proto “https” HTTPS=on”
In the forum you can find some posts about issues when OJS is behind a reverse proxy:
In gitHub you can find some posts too:
I’m starting my OJS 3.5 tests over traefik and till know I couldn’t make it work properly.
Something changed in 3.5 because same 3.3 settings are now working now.
If you succeed, please let us know.