Re: Flow creating new SharePoint list item - "Created By" help
HI @Anonymous,
Could you please share a screenshot of your flow's configuration?
Could you please show a bit more about the forms that you mentioned?
Further, do you want to save the creator of the form to Created By field of your SharePoint list?
I suppose that you want to save the user who completed the form into the Created By field of your SharePoint list, is it true? The Created By field is a system field and the value of it is filled by system automatically. The value of Created By field is based on the connection to the SharePoint connector.
In other words, if you create a connection to SharePoint connector (for using the "Create item" action) with your Office 365 account, when a new item is created in your SharePoint list, the value of Created By would be filled with your profile automatically. If you share your SharePoint list with other members within your Office 365 group or organization and they create a connection to SharePoint connector (for using "Create item" action and the List Name field set to your SharePoint list) with their Office 365 account, when a new item is created in your SharePoint list, the value of Created By field would be filled with their profiles.
In addition, if you want to save the user who completed the form into your SharePoint list, you could consider take a try to create a custom column to store the creator of the form on your side.
I assume that the form that you mentioned is Microsoft Forms, I have created a SharePoint list on my side and the data structure of it as below:
Note: On my side, I create a RequestorOfForm custom column to store the user who completed the form. The RequestorOfForm column is a Person or group type column.
I have made a test on my side and please take a try with the following workaround:
- Add a "When a new response is submitted" trigger.
- Add a "Apply to each", input parameter set to output of the trigger.
- Within "Apply to each", add a "Get response details" action, specify Form Id, Response Id set to Response Id dynamic content of the trigger.
Add a "Create item" action, RequestorOfForm Claims field set to Responders' Email dynamic content of "Get response details" action.
Image reference:
The flow works successfully as below:

Best regards,
Kris