Installation - Leiriad/-Neoforge-1.20.1-Inventorium GitHub Wiki
To access the Inventorium modpack, I invite you to download and install the Modrinth launcher. Why not CurseForge? The latter has been involved in several controversies lately concerning the security of its content, as well as the remuneration and protection of authors. You can find the Modrinth application here: https://modrinth.com/app.
Next, you can download the modpack here: https://modrinth.com/modpack/inventorium, and you’ll just need to double-click on it to start its installation.