Opening modal with linked data from button

Sorry but I can’t seem to figure out how to do something that is probably very simple.

I have a list of items that are pulled from a db table (image1.jpg). There is a button to add pricing for each line item (that doesn’t have a price). I want the button to open a modal and prefill some of the data that can be linked to the button that opens the modal (ie. ItemDesc=abd&Category=ThisCategory&paperItemID=ID). (image2.jpg) The highlighted yellow fields can be prefilled. The paperitemID would actually be a hidden form field on the modal as well.

I seem to be missing how I can add the variables to the button click that opens the modal. I know this is something simple but I haven’t been able to figure out the wappler way of doing it.

What am I missing?

Thanks,
Tom