@MF50
Unfortunately, Google Nest does not make it easy to update Wi-Fi settings.
It depends on which Google Nest camera and doorbell you have. If you have a 1st gen camera and doorbell that were installed in the Google Nest app, you can go to Settings | Home info | Home Wi-Fi help, then select the camera or doorbell, then select Start | Update settings. I think you may need to do this while you are still on the old Wi-Fi network, but Google Nest's instructions do not specify. If you don't find "Home Wi-Fi help", you'll need to remove your camera from the Google Nest app (again, I think, while you are still on the old Wi-Fi network), and then reinstall it in the Google Nest app while on your new Wi-Fi network.
If you have a 2nd gen camera and doorbell that were installed in the Google Home app, you'll need to remove the device from the Google Home app while the camera or doorbell is online (again, while on the old Wi-Fi network), and then reinstall it in the Google Home app.
If you are unable to do that, then you'll need to do a factory reset, which does require unmounting the camera and doorbell, and then reinstall it in the Google Home app.
Changing camera and doorbell Wi-Fi network:
https://support.google.com/googlenest/answer/9223711
Restart or factory reset Nest camera or doorbell:
https://support.google.com/googlenest/answer/9252162
