You can easily insert your payment link into your QuickBooks invoice template:
Click the Gear icon (top right) and select Custom form styles
Choose Edit next to your active invoice template
Go to the Content tab
Select the Footer section of the invoice preview
Paste your payment link, e.g. https://apron.me/yourcompany
Add a short line like: 'To pay online, please use the link below.'
Click Done to save
Your payment link will now appear on every invoice footer.