Print QR code on invoices

Hello friends, can help me with the QR code in the integration and code on the web, print in pdf when the invoices are generated from the link " invoice_url_key":

This https://www.xyz.com/xz/index.php/guest/view/invoice/xyzggerrdwfdvdyjtrgregr should not be the complete path to your invoice.

Then do the usual debugging to see what your output is