90 degree joinery?

There are a number of options here.

One is to use the Gantry Shift option:

and then make a vertical fixture of some sort:

to cut traditional joints such as box joints:

or dovetails:

Or, there is an option where one mounts the boards on a fixture at a 15 degree angle and then cuts them using a 30 degree V endmill — see:

https://fabrikisto.com/tailmaker-software/

Or, work up some sort of joinery arrangement where the parts can be cut flat on the machine:

If you’ll provide an example what you want to make and dimensions and stock thickness we can look into this with you here.