Invoice Link without having to first send it through DesignFiles

I would love the option to copy the link to an invoice PRIOR to sending it to a client, so that on our branded emails (specifically our very first appointment reminder email sent outside of DesignFiles), we can attach the link so that they have a button embedded to pay directly without having to send them separately. Currently, you have to send the invoice through DesignFiles first (which often goes to our client’s spam/junk) and THEN you can copy the link to provide for them. If we could grab it once the invoice has been saved as a draft, it would super helpful!