It looks like the problem here is that you have the distribution name “uma”, which is not one of the supported distribution names in the HashiCorp APT repository.
You can refer to Supported Debian and Ubuntu Releases to see what’s supported in this repository. As you’ll see, there’s no official support for Linux Mint, but as you noted Linux Mint is similar to Ubuntu, and so it’s possible that you could get a working result by using the Ubuntu release name that’s closest to your Linux Mint release.
Since you said Linux Mint 20 is similar to Ubuntu 20.04, I think the closest distribution name to try would be
focal, which you’d write instead of
uma in the APT sources file where you have
apt.releases.hashicorp.com currently configured.
With that said, I can’t promise that these packages will work anywhere except the distribution they are intended for. If you try this and find other problems once you have the package installed then I’d suggest using one of the other installation strategies that isn’t distribution-specific, such as downloading and extracting the original
.zip file that the APT and RPM packages are derived from.