I Use Tab in Hot Key Activities not working in Background

When my screen locked after insert few records hot key not working.In hot key I used Tab.
I used different approach for this
1.Used hot key for tab with click send error message.if any one reply me use simulate click.FYI there is no simulate click in hot key.
2.Used Type into with and add tab send error message
But not work.
I execute BOT for 8 hours with screen locked its execute successfully.But when I used Tab in hot key then it not able to work.
Can any one suggest there is any way we use tab.
I stuck in this issue from last two month but did not got solutions.

Hi did you try enable Send Window message for the send hot key activity?

yes I already used but not worked.As I mentioned above

is not Send Window message

Sorry due to typing mistake I mention send error message.yes used Send Window message this but not work.