Cannot save files onto external hard drive, no lock to unlock permissions!

I cannot add any files from my MacBook Air to my 2TB My Passport for Mac external hard drive by WD. I clicked on Get Info and at the bottom it says I can read only, but there is no lock on the bottom right to change that permission--contrary to every internet person's instructions to fix this. I ran the First Aid on the drive in the Disk Utility and it comes up healthy no issues to fix. I do not understand how to access and change this so I can save files to this thing. And I do not understand if it is read only, then how is my Time Machine saving backups to it???? This makes no sense. Please help! No it is not NFTS or whatever, it is APFS as you can see, which apparently is the format it's supposed to be for Apple. Can someone please tell me how to fix this. Literally everything I find shows to simply unlock it and change. There is no lock!