The Ring Doorbell 3 comes with a couple of wedges to adjust the angle of inclination and rotation of the doorbell to point it where you need it. However they provide only a limited range of options.

24 combinations of inclination and rotation angles between 0 and 20 degrees in 5 degree increments are provided with this model. The linked Onshape document provides a fully parametric model that allows you to set arbitrary angles. You may need to modify it if you wish to go above 20 degrees.

Other than providing different angles the wedge functions in the same manner as those provided with the doorbell itself. I would recommend printing in ASA for durability and UV resistance since it will likely be used outdoors.