I'm not sure what the actual question is and why you have an empty foreach loop in that snippet.

All the info is there

Connect-VIServer = "vCenter1","vCenter2","vCenter3","vCenter4"

Get-VMHost | 
Get-VMHostFirewallException | 
Where-Object {$_.Enabled -and $_.ExtensionData.AllowedHosts.AllIP} |
Select @{N='VMHost';E={$_.VMHost.Name}}, 
    Name, Protocols, IncomingPorts, OutgoingPorts, ServiceRunning
    

I thought we should do the same for all esxi in each vCenter.

The Get-VMHost should do that.
Unless your vCenters are not configured in LinkedMode, then you will have to run the same for each vCenter

that's what I was going to say, plus I'm trying to get the output per vcenter.

I'm trying to do my best, so far I think my level has improved a lot

If you get all the ESXi nodes for all vCenters, you can include the vCenter.

Connect-VIServer = "vCenter1","vCenter2","vCenter3","vCenter4"

Get-VMHost | 
Get-VMHostFirewallException | 
Where-Object {$_.Enabled -and $_.ExtensionData.AllowedHosts.AllIP} |
Select @{N='vCenter';E={([uri]$_.VMHost.ExtensionData.Client.ServiceUrl).Host}},
    @{N='VMHost';E={$_.VMHost.Name}}, 
    Name, Protocols, IncomingPorts, OutgoingPorts, ServiceRunning
    

it's possible to add the information related to IP?
I mean if it's set to All IP?
maybe it's me who is poorly expressed on the subject but here is the idea. in fact when you access "System", "Firewall" we find this information:
Service Name
TCP ports
UDP ports
Allowed IP addresses

If you filter on AllIP there are no individual allowed IP addresses in the result.