There are 3 types of OTA:
- BLE OTA with the mobile apps or ALTA
- OTA over bridge (M1 and M7 supported only)
- Wifi OTA (only for bridges or locks that have integrated bridges)
[If you have a 400 series of any SKU, with an M5 as it's bridge, it will always be able to OTA the M5 firmware over WiFi. You cannot OTA over bridge the 400 series though