I am trying to Update a person/group field on my flow. First, I have an array variable holding the names of the users, then I am selecting the index to get each of the elements from that array:

Then I am using this variable on Resolve person action. Question1: Where do i get the column field? Can i select it from one of the dynamic content under my get file properties action?

After this action, I have an update item which is configured to run after resolve person action has failed/ is successful. But I am getting error on my resolve person action:
Error 502
Guid should contain 32 digits with 4 dashes (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)

I check this solution here: https://veenstra.me.uk/2018/11/05/microsoft-flow-set-a-people-field-in-sharepoint-when-all-you-have-is-a-users-name/ but it is not working on my end. I dont know what did I miss on my flow.