How to activate installed mods?

Hello everyone,

I have installed some mods from the mod manager in aoe3 de, but im having a hard time trying to make it take effect in gameplay. The mod is called “higher limits”.

When selecting a skirmish mode it doesn’t let me select any mods. What steps am i missing? Ive messed with the scenario editor too but couldn’t come up with a solution. I just need it for the single-player mode.