I know a more complete solution to address the Postman Collection to JMeter Script conversion.

Check Loadium's postman2jmx converter out. It is open source project of Loadium team. https://github.com/Loadium/postman2jmx.git

You may use loadium.io or clone the project as you prefer. But I suggest using it through loadium.io following this tutorial => https://www.victorgarciar.com/jmeter-from-postman-collection-using-loadium

Happy testing! 😎🚀