In the Help command for 2022, here is the info for how to use the "APPLY Valley Gable"
Applying a Valley Gable to a Roof Plan
Using the Apply Valley Gable feature, any two adjacent roof edges can be converted into adjacent gables with a valley between them.
To Apply Gable to a Roof Plan
1. In Roof mode, select Edit ® Apply Valley Gable.
2. Place the cursor on the corner of the two adjacent roof edges you want to set to be gables.
Also look at the large ribbon under the EDIT menu while in the roof design ....took me awhile to work, but it is there and play around with the roof pitch at each gable ....some interesting roofs can be developed