DELETE an item and ignore the locked statement by using this Uri code:

/_api/web/Lists/GetbyTitle('KN Maintenance Blue Sheets')/GetItemById(5878)/recycle



UPDATE an item and ignore the locked statement by using this Uricode:
/_api/web/Lists/GetbyTitle('KN Maintenance Blue Sheets')/items(5878)/ValidateUpdateListItem()

An example of the JSON code required in Body - Editor and bNewDocumentUpdate are REQUIRED!

{

  "formValues": [

    {

      "FieldName": "LiveID",

      "FieldValue": "0"

    },

    {

      "FieldName": "MaintStatus",

      "FieldValue": "NEW"

    },

    {

      "FieldName": "AddedToMaintBy",

      "FieldValue": "[{'Key':'i:0#.f|membership|@{triggerBody()?['Author']?['Email']}'}]"

    },

    {

      "FieldName": "ITPowerAutomateFlowName",

      "FieldValue": "@{outputs('Compose_FlowDisplayName')} - OK"

    },

    {

      "FieldName": "ITPowerAutomateRunURL",

      "FieldValue": "@{outputs('Compose_FlowRunURL')}"

    },

    {

      "FieldName": "Editor",

      "FieldValue": "[{'Key':'i:0#.f|membership|@{triggerBody()?['Author']?['Email']}'}]"

    }

  ],

  "bNewDocumentUpdate": true

}