Adjusting the surface levels for the contact sensor

There is a 1/2 to 3/4 inch surface level difference between my doors/windows and the frame around them where I need to install the sensor . I called Ring to see if they have a solution for additional padding to be added under the main piece of the contact server. But they do not. Wondering how others have solved this problem. Are there 3M stickers / tapes with different thicknesses or velcro or … anyone has used?