Hi, I have downloaded and installed the trial version. And the trial version got expired. I would need to convert it into a community edition.
Presumably you mean ESXi? Please be clear as your post needs to be moved.
If so, there isn't a "community version", apart from using a vSphere Hypervisor licence which is free for non-commercial use: https://customerconnect.vmware.com/en/web/vmware/evalcenter?p=free-esxi7