You don’t just need WiFi, you need an Internet connection so the cam can contact the Wyze servers to get authorization to run for you. After you get that initial authorization, as long as you don’t power down the cam you can drop the Internet connection.
So, if you don’t have Internet at the remote location, try using a hotspot to get the camera to start up. Definitely test that before you go, though. Hotspots often have their own set of issues.
As for what nekcoes indicated above, that was written on May 9th. On May 10th in another discussion, WyzeGwendolyn said the need to contact the servers is expected behavior, and they don’t expect to change that in the future.
So hotspot may be your best bet.