Plex not working when streaming remotely with ipv6

Hi, I connect Infuse to my Plex. My plex is configured with ipv6. I don’t have a public ipv4. I can stream directly on plex website when i’m outside, while I cannot stream in Infuse. It shows “An Error Occurred”. My PMS is running on an Raspberry pi 4, my media file is stored in my Synology NAS. Is there any port I need to open in my firewall?