It's in the Go4 app under General Settings:
General Settings
- Units Imperial / Metric (Km/h) / Metric (M/S)
- Enable MF On / off
- Long Press Gimbal Control / Focusing
- Choose Live Streaming Platform > Facebook, YouTube, Weido, Custom
- Enable Amap (For China Mainland) On / Off
- Calibrate Map Coordinates (For China Mainland) On / Off
- Show Flight Route On / Off
Keep in mind though that when you're set to metric, everything shows metric. But when you change to imperial, some things remain as showing metric and unfortunately, I think height may be one of them. This has always been a DJI bug but I dunno, there's been so many updates lately that maybe they've fixed it. As an alternative solution, you could move to Canada. We're metric..........