Do you mind to expand the view for the "J-Link Silicon Labs" under the "Devices" view on top-left side of the launcher perspective?
I think first you need to be sure the target board was powered correctly. You should put the switch on the bottom-left side of the board to AEM position.
You could try to configure the target board and part though the "screwdriver+wrench" button under the devices tab.
It looks like the debug mode was "OFF", you could try to change it to "MCU" mode.
It looks like the firmware for the board is old, you could try to update the firmware through the "adapter firmware version:" on the launcher perspective.
Try if these steps helps or not if you never try some dangerous operation on the board and not sure if it was damaged already.
My views are my own and do not necessarily represent the views of Silicon Labs
Thank you for your advice. I've tried the steps you mentioned, but the bad ones are still the same. The test board switch has been hit to the AEM position because it cannot connect to the board. The firmware update failed. The debug mode automatically displays "OFF" and manually changes to "MCU". The same cannot be done with other operations! Thank you