On the middle right hand side you see 5 buttons:

"Audio" / "Midi" / "Loops" / "Fills" / "More"

Click the "More" Button

The Orange interface will expand.

Use the bottom pull-down and choose 3/4, 4/4 etc..

When you choose odd times like 5/4 you may not see any audio loops! The drummer has to have recorded in that time sig..

Hint: Choose "John Bishop" for a TON of 3/4 grooves