I just followed the Atlas CLI installation instructions on MongoDB's website here down to this part:

1. Create the list file /etc/apt/sources.list.d/mongodb-org-6.0.list for your version of Ubuntu. Replace 6.0 with your edition of MongoDB.
2. echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu/dists/bionic/mongodb-org/6.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-6.0.list
   There is a resulting file at /etc/apt/sources.list.d/ , and inside, it only has:

deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu/dists/bionic/mongodb-org/6.0 multiverse

But when I run sudo apt-get update , it says:

E: Malformed entry 1 in list file /etc/apt/sources.list.d/mongodb-org-6.0.list (Component)
E: The list of sources could not be read.

I technically have version 6.3, but there is nothing there if I go to that URL in my browser. Nevertheless, I've separately tried:

• changing the filename and contents to 6.3 instead of 6.0
• removing the [ arch=amd64,arm64 ] or multiverse bit just to narrow down the issue
• recopying and pasting the part in quotes directly into the file from the website
• deleting-recreating the file
• updating to the latest Ubuntu version?!

The error doesn't change with any of this. When I copy-paste the LIST file URL into my browser, it goes to the right place, so it has to be correct.
I do not know if this is connected to WSL, which causes all sorts of mysterious issues. Please help!