So I want to update a lookup field 'interface' which is multi-select.
My flow takes an Excel file and checks each row to see if it needs to update the SharePoint item or create a new one.
The file has the interfaces listed but not the IDs. I realised that I'd need these IDs from the SP list I'm looking up to.
So I added actions which basically used a Filter array, Select and append to string variable to get these into an array of all the IDs.
My inputs for Update Item look like this for interfaces on one of the items:
"{\"ID\":1264},{\"ID\":1265},{\"ID\":1266},{\"ID\":1267},"
However, my outputs are empty for this column. What could I be doing wrong?