SOLVED: Fast Reverse Proxy Rejects Connection

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UPDATE 2: I configured the TCP protocol alongside HTTP in FRPC.toml. On the FRPS interface, it is displayed as 'Online'.
I also set the JELLYFIN_PublishedServerUrl Docker environment variable to the following: http://jellyfin.domain.com.

However, I cannot connect to it either via the web interface or through the application. If anyone has any suggestions, I would greatly appreciate it. Thank you!