Most FSDO's have deployed the Designee Management System (DMS) Google FAA Order 8900.95 for DPE information. You make your application through the DMS system.
https://designee.faa.gov/#/login
All FSDO's are hurting for DPE's. The problem is that they also don't have the operations resources necessary to manage the DPE's. Kind of a Catch-22. Reach out to your local FSDO DPE Focal Point on their needs and ability to manage.