Help with Linux Mint 21.3 Installation

[ebeachlr]

I installed Jellyfin from the Linux Mint sources.  I wanted to set it up so that it is running at startup.  When I attempted to do the install as the web site suggests, for Linux Mint 21.3, I get the following message: E: Conflicting values set for option Signed-By regarding source https://repo.jellyfin.org/ubuntu/ jammy: /usr/share/keyrings/jellyfin.gpg != /etc/apt/keyrings/jellyfin.gpg
E: The list of sources could not be read.

I an a recent escapee from the Windows world and am trying to understand this Linux stuff.  Thanks for any help you can provide.


P.S. not that it matters but I have vision impairment and am 83 years old.