Solved.
You have to use vcenter to run the command. Trial version is fine
Also licences full version of vsphere esxi on the host is needed.
Just nav to the C:\Program Files\VMware\vCenter Server\TlsReconfigurator\EsxTlsReconfigurator
Run an elevated cmd and run "reconfigureEsx ESXiHost -h 198.51.100.2 -u root -p TLS1.0 TLSv1.1 TLSv1.2 "
Reboot the host
Then connect Image manager to host over TLS1.0 for a HSR.