Vekta Fields and Vekta Survey are distributed directly as Android APKs, installed on the DJI controller you already fly with — not through the Play Store. One Vekta account signs in to both.

Connect your controller to Wi-Fi and open the Vekta app once before going to the field. The app must contact DJI's servers on first launch to activate, and sign in to verify your licence. Required only once.
Vekta Fields needs RTK positioning. Vekta Survey works with RTK for centimetre accuracy, or GPS-only at metre level. See the compatible lists on the Fields and Survey pages.
The DJI controller you fly the aircraft with today.
Your NTRIP correction service login, for an RTK fix.
Create one — required to sign in and activate your licence.
Written for someone installing an app outside the Play Store for the first time.
Android will show a warning about installing apps from outside the Play Store. This is normal — professional and industrial apps like Vekta Fields are commonly distributed this way, directly by the vendor.