This is the first time I've used nix. On plutus-apps readme, I changed nix.conf but I don't know how to do this step.
2.On NixOS, set the following NixOS options:
nix = { binaryCaches = [ "https://hydra.iohk.io" "https://iohk.cachix.org" ]; binaryCachePublicKeys = [ "hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ=" "iohk.cachix.org-1:DpRUyj7h7V830dp/i6Nti+NEO2/nhblbov/8MW7Rqoo=" ]; };
If you're using an M1 Mac follow these instructions https://github.com/renzwo/cardano-plutus-apps-install-m1/blob/main/README.md
You should probably uninstall Nix first though (scroll to the bottom of that page to get a script for an easier uninstall)
I followed steps 4-6 in https://docs.plutus-community.com/docs/setup/MacOS.html and those worked for me (I have an Intel Mac - Big Sur). You could try them and see if they work for you. Those steps are:
Step 4. Edit the /etc/nix/nix.conf file:
nano /etc/nix/nix.conf
note, you will have to create that file if it doesn't exist
Step 5 - Add these lines to the file:
substituters = https://hydra.iohk.io https://iohk.cachix.org https://cache.nixos.org/
trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= iohk.cachix.org-1:DpRUyj
Step 6 - Restart your computer - important that you do this
