Here is the example command to replicate all AD in powershell command:

function Replicate-AllDomainController {
(Get-ADDomainController -Filter *).Name | Foreach-Object {repadmin /syncall $_ (Get-ADDomain).DistinguishedName /e /A | Out-Null}; Start-Sleep 10; Get-ADReplicationPartnerMetadata -Target "$env:userdnsdomain" -Scope Domain | Select-Object Server, LastReplicationSuccess
}