When entering the game for the first time with a save file, enable promods 2.71 mods in the mod manager. (We need to do this once, we won't do it later.)

The required promods files are listed below:
(Documents > Euro Truck Simulator 2 > promods files that should be in the mod folder are as follows)

✅ "promods-assets-v271|ProMods Assets Package"
✅ "promods-model3-v271|ProMods Models Package 3"
✅ "promods-model2-v271|ProMods Models Package 2"
✅ "promods-model1-v271|ProMods Models Package 1"
✅ "promods-media-v271|ProMods Media Package"
✅ "promods-map-v271|ProMods Map Package"
✅ "promods-def-v271|ProMods Definition Package"
✅ "promods-dlcsupport-v271|ProMods DLC Support Package"

* The file named ProMods DLC Support Package (at the bottom) is extracted from the zip file that we extracted the promods files.

The 8 files above regarding Promods 2.71 should be in the mod folder. (Promods v2.71 requires us to have all the Map DLCs in the ETS2 game.)

The order of priority when activating mods: For example, it can be as seen below.

DLC Support Package
Definition Package
Map Package
Media Package
Model 1
Model 2
Model 3 Packages
Assets Package