Use APKPure App
Get Pentax Image Sender old version APK for Android
Wifi image file transfer app for Ricoh and Pentax Camera
Support : Pentax K-1, K-1 Mk II, K-3 MK II, KP, K-S2, K-70, Ricoh GR II, GR III
Manual : https://blog.naver.com/knight7898/221502699137