As MarkerInbound says, you call Tucson Approach on the phone for clearance. That info and phone number, are listed here, Clearance Delivery Phone 520-829-6121, in the FAA Chart Supplement:
Page 55 (faa.gov) Back to CTAF frequency for taxi and departure, then call Tucson frequency when airborne. This is common standard procedure for remote non-towered airports throughout the US, (with appropriate phone numbers, of course,) where you can't contact ATC by radio.