Modified By in Content Approval Status action in Serial Approval flow

[AntoinetteB]

I have read the article linked below.  I don't have coding experience, but I've looked at it long enough to have a basic idea of what it is trying to accomplish.  Before I try to set it up myself though, there is something I cannot understand.

I want the Modified By field to start as the User who manually selected the document and started the flow.  This works fine.

But then, I want the Modified By field to change to the person who responded to the Approval action, which is also the same person who the Set Content Approval Status "Comments" field should be coming from, except that in Version History the  Comments field appears as if the Requester was the Modified by.  I want the Approver.

I have been referred to this link for instructions to do this, but I don't see the step that tells the code how to find the person who responded the the Approval action, and to change Modified By to their name.  Can someone tell me which step this is or give me another way to do it?  

http://johnliu.net/blog/2019/2/flowninja-hack-78-modifying-modified-by-and-modified-time-with-micros...

I have also tried many things not related to the linked solution above, such as Apply to Each with Responses Approver, and Get UPN.  I'm getting ready to try check in/check out actions I don't need just to see if I can get this darn flow to update the Modified By field to the approver who just did the actual changes and approval.

[Pstork1]

You sent the approval to a particular user.  That is the person who approved when the response is returned.  You can use that same person to update the modified by field. If you send an approval to multiple people you won't have the opportunity to change anything until all the people have responded. So if you are doing a multiple person approval, rather than a serial approval, then there is no way to accomplish what you want to do.

[AntoinetteB]

Thanks, yes I sent the approval to 2 particular users, and the first one to respond takes it out of the queue.

This is a serial approval, first to respond.

The part where you said you can use that same person to update the modified by field, I am trying to do just that.

But I can't figure out how.

No matter what I try, the requester who ran the flow to request approval for the selected file comes out in the modified by field,  instead of the person who they sent the approval to who responded (approved/rejected) it.

Every comment in the Version History shows Modified By the user that selected the file.  No matter which person in the series approves.  I'm actually thinking of just coding the comments to include the approvers name.  So it will show as Modified by Person A in the version history, but the comments will read "approved by Person B through Power Automate."  As a workaround.   Since I can't the Modified By field to update.

[Pstork1 · Accepted solution]

Ok, if you send the approval to two people with first to respond then the email address of the responder will be in the response object that is returned.  You then need to use that email in the REST call to change the modified by field of the item.  There is no way to get flow to use anything other than the maker because it is doing the modification.

[AntoinetteB]

Thank you.  A REST call is way out of my wheelhouse so I cannot try it but it sounds to me like this is answering the question I asked.  I will mark as solution for the benefit of others finding it more easily.  I taught myself VBA to code an excel doc to create a Word doc and move some of the text over that that's the extent of my coding skills and I don't want to hose up anything because my custom built flow is actually working with no errors and I consider that a miracle.

I am instead going to solve my problem by adding check out/check in and Content Approval actions with comments coding in the names of the approvers.  So my version history look like:
Modified by:  <Requestor name>    v1.0  XYZFileName Approved by <Responses Approver Name> through Power Automate.