I know this can be done easily via Lua or other modules, however I cannot recompile Nginx in this scenario.

These are the only ones that nginx -V shows:

--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-auth-pam
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-cache-purge
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-dav-ext
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-ndk
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-echo
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-fancyindex
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/nchan
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-lua
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/rtmp
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-uploadprogress
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-upstream-fair
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-subs-filter
--add-dynamic-module=/build/nginx-qv2Nx5/nginx-1.18.0/debian/modules/http-geoip2

I don’t see fastcgi_pass in these modules either, so what options do I have? Do I really have to use proxy_pass and run an additional service for that?