Install the Splashtop Remote Support Console, download from: https://www.splashtop.com/downloads

• Choose "Splashtop Remote Support"
• Choose "Windows 11, 10, 8, 7 ...", download and install
• Launch the app from the start menu and log in using the credentials sent to you as part of the invite you received.
• Click the SOS button and enter the code provided to you by the client you are assisting

You will see this window which will be used to enter the code the client provides you: