I am unable to use my pen drive because it's shown as no media. What to do next?

Hi @emmatf and welcome to the Manjaro community.

As a new user, please take some time to familiarise yourself with Forum requirements; in particular, the many ways to use the forum to your benefit:

You have not provided any actionable information. At the very least, please provide system information; the output from:

inxi --admin --verbosity=8 --filter --no-host --width

Please read through the links above to understand what we need from you when placing a support request. As receiving support is clearly the intention, I have also moved your thread to an appropriate category.

Cheers.