Rocket.Chat rate limiter


I have a question regarding the rocketchat rate limiter and reverse proxy configuration. The setup is: reverse-proxy -> UCS with rocketchat installed. If for example someone tries to bruteforce rocketchat, it will block the internal IP of the reverse proxy instead the original client IP. I’ve found the following issue on github:

“To get the correct IP the sys admin needs to define the HTTP_FORWARDED_COUNT env var to a value of the number of reverse proxies in front of it.”

My question is how can I configure this env var on UCS?

Thanks in advance.