MacOS External USB Storage Permissions Issue

[RSA]

Brand new here - moving away from Comcast and TiVo. I'm excited to get Channels DVR set up, but I've run into a brick wall of sorts. Apologies if I missed it, but I've spent a couple of hours searching here and elsewhere however I cannot find a clear answer to the issue.

I'm setting up Channels DVR on an older iMac running macOS Catalina v10.15.7. When I try to set up the recording directory on an external HD (Seagate 8TB USB 3.0) I get the following message:

"Error: unable to create dvr directory: mkdir /Volumes/DVRs/channels-data: operation not permitted"

I've tried changing the USB drive's formatting (Mac OS Extended, APFS), folder names/locations, R/W permissions, sharing for files, media, etc. No matter what I do I immediately receive the same message when I attempt to associate Channels DVR with the external drive.

I was able to create a folder on the internal HD and set up Channels DVR to use it successfully, however it's a 1TB SSD and I'd prefer to use the larger external HD. From all I've read this setup should work, but...

I'd be very grateful for any assistance.

TIA!

[tmm1]

Go to system settings under privacy and grant access to removable drives

[RSA]

That (more or less) did it!

More or less because it's just slightly different with macOS Catalina - hadn't used it in a couple of years but I got the gist of it and dug around. It's under System Preferences > Security and Privacy > Privacy > Files and Folders. Found the external drive and checked "Removable Volumes". Ta-dah!

Now I have to sort out why some of the channels from the providers aren't showing up. But that's for another day.

Thanks very much, it's truly appreciated!