Apple released macOS 10.15 Catalina on October 7, 2019. This new release has stricter security requirements that require explicit permission to allow Splashtop applications to have control and work properly. Same thing for Apple's newest operating system Monterey macOS 12.
Video of setup
See step by step below
After you download and open the sos.dmg you will need to add each permission below under the Security & Privacy in System Preferences.
Our guided window helps open each section. Click Allow and follow guide.
Click the unlock on bottom left
Then under Accessibility add the SOS app by clicking the + sign or checking box next to the Splashtop SOS, if already there.
You will do the same process for the other two permissions: Screen Recording and Full Disk Access.
After that you will get the Success window with 3 green check marks. You technician should be able to have full control of your Mac.