You can open and play the RTSP Stream from the RTSP client tool like vlc.
1. Set RICOH THETA in Wireless LAN client mode.
Video: How to Use Wireless LAN Client Mode
Check out the manual: https://theta360.com/en/support/manual/v/content/prepare/prepare_08.html
2. In the basic app for smartphone, select "Settings" > "Camera settings" and set "THETA RTSP Streaming" in "Plug-in", then tap the icon displayed next to "Starting plug-in".
If the application is launched successfully, video LED on RICOH THETA turns on.
3. Find out and remember the IP Address of RICOH THETA.
i. Open the basic app for smartphone.
ii. select "Setting" > "Camera setting" > "Camera version", then get IP Address.
4. Receive live streaming from RTSP client application like vlc.