How to add a new server to the farm to an existing search topology

We are running SharePoint 2016 on-prem. I detached a  server that was part of the farm and also had the   Content Processing, Analytics processing . When I reattached the server to the farm it no longer was part of the search topology with the components specified.

My question is 1) how can I add it to an existing search topology  

Error while cloning:- 

$sa = Get-SPEnterpriseSearchServiceInstance -Local 
$clone = $sa.ActiveTopology.Clone() 

PS C:\Windows\system32> $sa.ActiveTopology.Clone()
You cannot call a method on a null-valued expression.
At line:1 char:1
+ $sa.ActiveTopology.Clone()
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull