In any case, I will share all my findings with you all. I was hoping for some support since I don’t have experience with such an implementation.
But I have already added the QR code in the template. Now I need to import the other information in this QR Code template.
These are the variables for the invoice recipient information:
$invoice->client_vat_id;
$invoice->client_address_1;
$invoice->client_zip;
$invoice->client_city;
$invoice->client_country;