In some situations the client is unable to enter the session code via keyboard. Touch pad can be used as an alternative. Follow the steps below to enable it:
Right-click the "Settings" button and click "Show Touch Pad" option.
Use the touch pad to enter the session code.
Note: The button in the bottom left serves as an alternative for the "Delete" button and the button in the bottom right serves as an alternative for the "Enter" button.