Due to firmware upgrades or resets, the rtsp streams might not be available anymore. After a whole afternoon trying and swearing I found the solution, which is very well hidden.
Follow these steps:
Step 1: Ensure the camera and your phone are under the same network
Step 2: Open EZVIZ app,
Step 3: tap the profile icon on the top left > Settings > LAN Live View > Start Scanning
Step 4: Tap the camera you need to use, input the password, which usually is the 6-digit capital letters code on the white sticker of your camera
Step 5: Tap the gear-like icon on the top right > Local Server Settings > enable RTSP
I hope a prevented you from waisting an afternoon as well.