home manager: configure applications' settings in ~/.config, but do not install the binary in ~/.nix-profile/bin?

i'm using home manager on a non nixos distro (gentoo), and I like it because I can declarative configure my programs, eg firefox nushell etc etc. but, each time I have to unlink some programs in ~/.nix-profile/bin/ because they get picked up instead of the one that are native to my system (managed via package manager).
i've been unlink manually, but is there a way to tell home manager "just configure this, don't install the binary"?