Proxy Pass frontend to Nodejs backend


I'd like to do the following; -> proxy pass to

If view the site via the IP:port I see what I should be seeing, but not sure how to proxypass the domain to the node port in open lightspeed.

I'm able to do this with nginx, but am quite new to OLS.

I've tried a rewrite rule in .htaccess

RewriteEngine On
RewriteRule ^(.*)$$1 [P]

Which just shows an error 500

Any help / pointers appreciated!