If you did installed APX driver.. Do this:
Connect your Switch to your PC via USB and ensure it is powered off
Enter RCM on your Nintendo Switch
Insert your RCM Jig into the Right Joycon slot, sliding it all the way downHold down the [Vol+] button and press the [Power] button, the Switch will now enter Recovery Mode (RCM) but the screen will stay off
The icon in TegraRCMGui should now read [RCM O.K.]
Connect your Switch to your PC via USB and ensure it is powered off
Enter RCM on your Nintendo Switch
Insert your RCM Jig into the Right Joycon slot, sliding it all the way downHold down the [Vol+] button and press the [Power] button, the Switch will now enter Recovery Mode (RCM) but the screen will stay off
The icon in TegraRCMGui should now read [RCM O.K.]