If you just need to export your collection, this might help.
https://www.getpostman.com/docs/v6/postman/collections/data_formats
Or
Right click collection and choose Export:
I want to convert my current Postman collection(s) to JMeter jmx files
I should be able to convert in loadium by adding collection JSON file, But I don't find Export option anymore (even I'm sign in to postman), was it removed ?
How/where collection JSON are saved?
I didn't find a valid answer here (sharing) or here (Postman uses LevelDB)
If you just need to export your collection, this might help.
https://www.getpostman.com/docs/v6/postman/collections/data_formats
Or
Right click collection and choose Export:
@user7294900 The export button is available in multiple places in the app. Not only in the context menu. It's there in case you're browsing the collection by clicking the '>' arrow over each collection. It's there inside the '...' over each collection.