For Nginx Proxy Manager, you shouldn't need to add anything. I believe the default config is to use x-forwarded-for headers. Can you show me a screenshot if what you currently have in the known proxies field?
Jellyfin 10.10.7 (Docker)
Ubuntu 24.04.2 LTS w/HWE
Intel i3 12100
Intel Arc A380
OS drive - SK Hynix P41 1TB
Storage
4x WD Red Pro 6TB CMR in RAIDZ1