Automatically fill a single text column in Lists by the value of a Person Field column

Femke11 You cannot use person or group columns in the calculated column formula. So, you cannot get user name from person field using calculated columns.

Above JSON I provided in my response only works for showing the email in list view. It is not saving the actual email/name value in the column. So, you cannot use it in lookup columns.

If you want the actual value to be stored in the column, you will have to use the Power automate flow on item creation/update. Follow this response: Automatically fill a single text column in Lists by the value of a Person Field column 

Let me know if you are stuck while creating such power automate flow, I will try to show some examples in that case.

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Femke11 The people fields in JSON formatting supports the following properties (with example values): 

{
  "id": "122",
  "title": "Kalya Tucker",
  "email": "email address removed for privacy reasons",
  "sip": "email address removed for privacy reasons",
  "picture": "https://contoso.sharepoint.com/kaylat_contoso_com_MThumb.jpg?t=63576928822",
  "department":"Human Resources",
  "jobTitle":"HR Manager"
}

You can get the name of users using the title proeprty.

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Femke11 If you don't want users to click on every list item/row to get the email address, you can use the When an item is created or modified trigger in the flow and use logic given by RobElliott for updating list item with email address.

To avoid the infinite flow running loop, you will need to add additional logic at the starting of flow to check if person or group column is changed since last update and based on that condition, you can update the email address column.

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