Set lookup columns by workflow sharepoint list

ListA

• Col: UID
• Name
• Age
• Address

ListB

• Col: UID
• List A
• List A: Name
• List A: Age

Copying entire UID column from one list to another.

ListA:

1. Put a workflow in ListA, and trigger it when "Start when items are created" in workflow settings
2. Make the workflow as below:
   

The flow copies the content of UID column in List A, and fills in an empty column called Helper Column with the ID of the row, and the UID in Column. The helper column is needed for lookup in list B.

ListB:

The 'List A' column in ListB is a lookup column. You can have the workflow to set the value in lookup value by below workflow:

Set the workflow to trigger when item is created. then it runs just after the other workflow.