Skipping acquire of configured file 'https://apt.postgresql.org/pub/repos/apt focal-pgdg InRelease' doesn't support architecture 'i386'

I have recently installed Ubuntu 20.04 LTS and I am a bit fresh user for ubuntu. after installing postgresql 14, and I ran sudo apt update. Then it says

N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'https://apt.postgresql.org/pub/repos/apt focal-pgdg InRelease' doesn't support architecture 'i386'

Already tested /etc/apt/sources.list.d/pgdg.list changed from

# deb http://apt.postgresql.org/pub/repos/apt/ focal-pgdg main

to

# deb [arch=amd64] http://apt.postgresql.org/pub/repos/apt/ focal-pgdg main

but still the message shows up

The file was like this

deb http://apt.postgresql.org/pub/repos/apt/ focal-pgdg main
# deb [arch=amd64] http://apt.postgresql.org/pub/repos/apt/ focal-pgdg main

then I changed

deb [arch=amd64] https://apt.postgresql.org/pub/repos/apt/ focal-pgdg main 
# deb [arch=amd64] https://apt.postgresql.org/pub/repos/apt/ focal-pgdg main

then it worked. It seems it is important to add [arch=amd64] and put "s" in https