Hi @Akshayini,
Welcome to the forum!
It seems to me that the issue here is with PowerShell rather than with Prometheus extension: is that what you’re using? Looking at this SO question, PowerShell simply doesn’t allow passing env vars in this way. I think it makes sense to try the workaround suggested in the above SO question. Otherwise, you could also try passing parameters in CLI or JSON. Here’s an example of CLI syntax:
./k6 run script.js --out output-prometheus-remote=url=http://localhost:9090/api/v1/write
I hope that helps 