How to import new widget json file to Habpanel OpenHab 1.8.3?

As the title said, anybody can show me how to import new widget json file in habpanel? I’m using OH version 1.8.3?
Please, I’d be very appreciated!

Any help please?
When I choose “Advance settings” in habpanel, there is a notice says that: "Panel configurations are not available: not running openHAB 2 or service not installed?"
Is that why I couldn’t see any selection to import widget json file?
I’m using openhab 1.8.3