Currently, there is no way to import from JSON format. And most of the clients are not supported. Like currently, I'm using Hoppscotch, which is also an open-source app.
There is an option to export everything as JSON, and most of the programs have this feature. But when I tried to import, it failed. As it doesn't support that functionality.
Atleast add the functionality to import everything in JSON format also. So that people doesn't face any issue during migration.