I would say that most certainly the URL is not correct. The URL seems a little bit odd to me. Where did you find that? Was it here http://www.eye4.so/FAQ/943 I see they use UDP so did you set stream type to rtsp_udp ?
I also see that to get audio and video they say Secondary stream + Audio: rtsp / ip: port/udp/av1_1 so in the URLs below it should maybe be /av1_x
Here are my suggestions:
1. The camera supports the ONVIF standard. When adding a new source use the tab ONVIF Source and search for it there. Hopefully it will find the camera there. If not, continue.
2. There are 2 things in the URL that I like you to change and test when adding as Custom URL:
Set Stream Type to rtsp_tcp.
a. I like you to change udp to tcp
b. normally cams that support ONVIF use standard ports so I like you to change 10554 to 554 which is standard for rtsp.
c. or when it is ONVIF it can also be as simple as:
3. If nothing of the above works I see that the cam have a Hisilicon processor built in. So test
Sometimes you can figure out the correct URL from the configuration in the camera.
Adding a cam is not always straight forward, but I hope some of the suggestions or combinations above will solve the problem.
Good luck and please report back how it goes to help other users in the forum.