The suggested technical procedure would be:

(1) You offer an API that takes a download link as a parameter.

(2) I send a request to your API with the download link where the SVG can be found.

(3) You download the SVG and prepare design options for the customer. You respond to me with a purchase link for my customer.

(4) I forward the link to my customer and earn a small provision if the customer purchases any goods with that design of his.