Birdnet behind Nginx reverse proxy

[Klages]

I tried to put birdnet behind a nginx reverse proxy, as I have other services already behind it.
With an HTTP forward, I get a "The page isn’t redirecting properly" error message. If I select HTTPS it tells me "502 Bad Gateway"
Has someone already done this and could point me in the right direction on what I have to change on birdnet side to get connectivity via a reverse proxy?