Note: currently, some battery-powered cameras, such as Tapo C420, C400, and D230, do not support being viewed via the RTSP/ONVIF stream.

1. If the camera has subscribed to the Tapo Care service and inserted a microSD card, the RTSP stream can’t be established.

2. Check if the configuration on the camera is correct.

The link below includes some basic parameters that need to be configured on the camera.
How can I connect my Tapo camera to a NAS or NVR?
 

Note: Try to change the camera account(username and password) if they include special characters.

3. Check your network diagram, and confirm if you are streaming the camera locally or remotely.

If you are streaming the camera remotely, more configurations are required on your home network, for example, open port 554 or 2020 on your router for the camera, and find the public wan IP address on your router.

For example, the typical network diagram of streaming a camera via RTSP protocol on a PC locally: 

4. Confirm the detailed phenomenon on the third-party apps/programs.

For example:
1) Third-party apps/programs are used, such as iSpy, VLC, etc.
2) The URL used to stream the camera, for example, rtsp://IP Address/stream1(For high-quality stream1).
3) The error message that appears if there is one.

5. Try to stream the camera on a PC with an iSpy or VLC program. 

How to view Tapo camera on PC/NAS/NVR through RTSP/ONVIF Protocol? 

Note: If several devices watch the camera simultaneously, close the Tapo app, and disconnect other RTSP/ONVIF connections first.

Please reply to this thread or start a new thread with the following information to get further help if the RTSP/ONVIF stream cannot be established. 
 

1. The results of the above steps.

2. Collect the camera log if possible.
How to get the log of Tapo Camera?

3. The MAC address of your Tapo camera. You can find the MAC address on the camera’s Device Settings>Device Info page, and please send it to me(@Solla-topee) via a private message.