Absolutely the wrong way and probably not legal way to collaborate modpack development.

Install/Setup https://prismlauncher.org/

Clone the repo into ....PrismLauncher/instances

Restart prism and it should appear.

Edit the pack config to not allocate more memory than you have, I tried changing it off of 16GB but it still launched at 16 for me.

Adding mods to the pack:

Generally prefer modrinth over curseforge, just so that we don't screw up and add the same mod twice. Some mods haven't been uploaded to modrinth yet, so sometimes it isn't an option

Make sure the game loads into a world before pushing.