Hi @patrick2020 and thanks for your query. Unfortunately the Tobii software does not currently support emulated key inputs and will only work with physically pressed keyboard strokes.
One possible workaround is that you can have the mouse cursor move by a specific amount (larger than the buffer specified in the Tobii settings) every 500ms and see if that works?
You can set the cursor position in .NET as explained @
https://docs.microsoft.com/en-us/dotnet/api/system.windows.forms.cursor.position?redirectedfrom=MSDN&view=net-5.0#System_Windows_Forms_Cursor_Position
Please try it out and let us know how you get on. Best Wishes.