Append a Relationship picker with action

[BenoitAnastay]

I have a list of tools (physical assets) that I want to link to toolboxes, a toolbox will contain multiple tools but a tool is linked to only one toolbox.

I want to be able to read the barcode on a tool and add it to the toolbox I currently edit (append the picker)

With SQL the request would be easy as

UPDATE tools SET toolbox_id = $box_id WHERE code=$barecode

But I don't know how I can do that with budibase and updating the relationship picker is the intended workflow but I don't know how to append a list of scanned barcodes to it.

My scanner work as HID device and can terminate with TAB that let me use on update action.

So on uodate I filter the string since it's GS1 then second step I would like to add the value entered in the text box to the relationship picker.

Any advices ?