Using column formatting on Person or Group type field you can only access below properties as of now (with example values):

{
   "id": "122",
   "title": "Kalya Tucker",
   "email": "[email protected]",
   "sip": "[email protected]",
   "picture": "https://contoso.sharepoint.com/kaylat_contoso_com_MThumb.jpg?t=63576928822",
   "department":"Human Resources",
   "jobTitle":"HR Manager"
}

Official documentation:

Column Formatting in SharePoint - Special string values - Check People fields section

Using column formatting on Person or Group type field you can only access below properties as of now (with example values):

{
   "id": "122",
   "title": "Kalya Tucker",
   "email": "[email protected]",
   "sip": "[email protected]",
   "picture": "https://contoso.sharepoint.com/kaylat_contoso_com_MThumb.jpg?t=63576928822",
   "department":"Human Resources",
   "jobTitle":"HR Manager"
}

Official documentation:

Column Formatting in SharePoint - Special string values - Check People fields section