@unknow
I solved this problem using HotKey Tech Tabs, thank you!

And how do I switch between Tech pages quickly, only with a mouse click?

How do I use the mod in the campaign in offline mode?
In the vanilla case just put the TF_CampaignModEnabler_FA.scd file into gamedata and it will work.
But I put the file in FAForever\gamedata and it didn't work.

Is there a UI mod for a larger building bar?
Or a shortcut to control the four buttons on the building bar.
Leftmost, Left, Right, Rightmost.
If you use too many mods that add units and buildings, the building bar will be long and I'm looking for a way to make it easier to do that.