Delete packagecloud repository and key

So I've ran a sudo apt update and got some errors:

N: Skipping acquisition of configured file 'main/binary-i386/Packages', as repository N: 
Skipping acquisition of configured file 'main/binary-i386/Packages', as repository 
'https://download.mono-project.com/repo/ubuntu stable-focal InRelease' doesn't support 
architecture 'i386'
 W: GPG error: https://packagecloud.io/shiftkey/desktop/any any InRelease: The following 
 signatures couldn't be verified because the public key is not available: NO_PUBKEY 
B7E65990E879472F
E: The repository 'https://packagecloud.io/shiftkey/desktop/any any InRelease' is not 
signed.
'https://download.mono-project.com/repo/ubuntu stable-focal InRelease' doesn't support 
architecture 'i386'
 W: GPG error: https://packagecloud.io/shiftkey/desktop/any any InRelease: The following 
  signatures couldn't be verified because the public key is not available: NO_PUBKEY 
 B7E65990E879472F
E: The repository 'https://packagecloud.io/shiftkey/desktop/any any InRelease' is not signed.

I've searched for information on how to remove that repository but haven't found any clear answer

When I try to remove the GPGkey I get "no data found" so can't delete they key also. Does anyone know how to get rid of those errors?

1. ls /etc/apt/sources.list.d/

Look for the name of the repo you want to remove, or if you're unsure, open the file with any text editor, if it mention the name of the repo you want to remove (in my case it has 'packagecloud.io' and 'git-lfs') then you should be good to go

2. rm /etc/apt/sources.list.d/<insert file name here>

hope this helps