Navigate over to the products page and view the table of products.
Find the product you wish to upload assets too, and click the grey arrow at the beginning of the desired product row, then choose the variant you would like to work on.
This will load you into a 'Assets' page. From here you can click the Limit button located near the end of the row, and type a new limit. This will limit how many times the file can be downloaded using the same download link sent to a customer.
Please note, if you want unlimited, simply set the limit to 0.
