//free\\: Nexus9300v.9.3.9.qcow2 Download

cd /opt/unetlab/addons/qemu/

Before you proceed with the download, ensure your host machine can handle this virtual switch. The Nexus9300v is resource-heavy compared to an IOSv router. Nexus9300v.9.3.9.qcow2 Download

You're looking for information on downloading Nexus 9300v, specifically version 9.3.9, in qcow2 format. Here's what I found: specifically version 9.3.9