Have working BG3MM installs.
and (if you cant quick install via BG3MM Tools menu) BG3SE
Click the folder icon to the right of shortcuts to open your bg3 mod directory. To join us with 80 mods it’s easier to start with a clean directory.
It should open wherever your \Users\<your_username>\AppData\Local\Larian Studios\Baldur’s Gate 3\Mods lives. This is where mod pak files go.
Unzip the pak zip file into this directory.
Click the refresh button left of the shortcuts one to refresh what the mod manager sees.
Your mods may be on the right hand inactive column. You can ignore that and proceed to the next step.
Import Order from File
This is where you select the JSON File. This should move everything from the inactive panel to the active panel and put them in the proper load order.
Export order to game.
Go launch game.