No, it doesn't need to be permanently connected to Wi-Fi to record locally; it can record to a MicroSD card without a continuous Wi-Fi connection.
However, without a Wi-Fi connection you won't be able to watch the live stream, play videos or receive notifications on your smartphone via the Tapo app.

Practical details:
- During initial configuration, the camera must be connected to a network (wired or wireless) to be added to the application.
- Once configured, the camera continues to record locally on the MicroSD card (24/7 recording or detection) even if Wi-Fi is cut off.
- To view from your smartphone in real time and receive alerts, the camera must be connected to the Wi-Fi network (or to an access point/mobile router); without this, remote access is not possible.
- Some Tapo products can use a "Wi-Fi backup" function via a compatible Tapo hub, but this requires additional Tapo hardware and does not replace Internet access if you want remote access.

Suggestion for use in a camper van:
- You can use the camera off Wi-Fi to record on MicroSD and then view the videos by removing the card or reconnecting the camera to the network to transfer/view.
- If you want to view live video from the road, you will need to provide the camera with a local network (e.g. a 4G/5G hotspot on your phone or a mobile router in the camper van) and reconnect the camera to this Wi-Fi.

I'm not entirely sure of the exact initial setup procedure specific to this model in a motorhome (e.g. mobile hotspot restrictions) - the information provided above is from general Tapo documentation. For more details, see the Tapo C520WS installation guide or the Tapo FAQ.