How to add tarball to nix store (Citrix Workspace)

The citrix_workspace package requires the tarball to be part of the /nix/store before the package can be installed. The package suggests to manually download the tarball and then run nix-prefetch-url file://[path/to/tarball] but how can I do this declaratively in a flake configuration? Without knowing exactly how to do this my guess is that I can either manually download the tarball and include it as part of my flake repo (and somehow add it to the nix store by evaluating its path?) or including the URL of the tarball as an input with flake=false (does this automatically add it to the store?). Can you provide an example of how to do this?

I tried to include the URL as one of my inputs as follows:

    citrix_workspace_2302.url = "*~hmac=f37429dfa2fd8cd56f2640cf19ffe2b8e058e79350ec81b6daa4ddbca303e410";
    citrix_workspace_2302.flake = false;

But for some reason any forward slashes after the ‘?’ are replaced by ‘%2f’. So the URL used by nix ends up being:*~hmac=f37429dfa2fd8cd56f2640cf19ffe2b8e058e79350ec81b6daa4ddbca303e410

You probably want to use fetchurl instead.

Thanks. So where/how would I include it in my config?