To backup the ESXi configuration we can do this via the esxi shell.

First we need to Sync the config by running this

vim-cmd hostsvc/firmware/sync_config

To back-up the configuration data run this command

vim-cmd hostsvc/firmware/backup_config

This command will output a URL which can then be downloaded by a remote client.

You can use curl, wget, or even a browser to download the file.

https://kb.vmware.com/s/article/2042141

First rename the configuration file to

configBundle.tgz

Now Put the host into maintenance mode by running this command

vim-cmd hostsvc/maintenance_mode_enter

Copy the backup configuration file to the ESXi host or an available datastore (or mount a NFS volume and put it there)

Run this command to restore the ESXi hosts configuration (replace backup_location with the location you put the file)

vim-cmd hostsvc/firmware/restore_config /backup_location/configBundle.tgz

If you receive a UUID mismatch, then you can override this by adding a 1 (digit 1) after restore_config, but this will ONLY work if you are not using TPMS.

vim-cmd hostsvc/firmware/restore_config 1 /tmp/configBundle.tgz

Executing this command will initiate an automatic reboot of the host after command completion.