You can find ESXi license keys through various channels:
Students and teachers can obtain free or heavily discounted ESXi licenses through the VMware Academic Program (VMAP). Check if your university participates. esxi 9 license key github
Find the for the ESXi 8.0 evaluation.
Environments without internet access must use a manual process of generating a request file, uploading it to a Broadcom portal, and downloading a signed response file to activate the software. You can find ESXi license keys through various