Patching Powerapp to Sharepoint List anonymously

barryjarvis 

You will need to use a Power Automate flow that performs a "Send an HTTP Request to SharePoint" Action to the url

_api/web/lists/getbytitle('list name')/items(<itemid>)/validateUpdateListItem 

using this body

{ 

  "formValues": [
                   {
                     "FieldName":"Title",
                     "FieldValue":"my new Title"
                   },
                   {
                     "FieldName":"MyOtherField",
                     "FieldValue":"mynewValue"
                   }
                ], 
  "bNewDocumentUpdate":true 

} 

You will have so specify which fields to set in the json array

https://www.concurrency.com/blog/may-2022/performing-a-system-update-of-a-sharepoint-list-item-through-power-automate
https://techcommunity.microsoft.com/t5/microsoft-sharepoint-blog/update-file-metadata-with-rest-api-using-validateupdatelistitem/ba-p/1365682