I'm here to share details about the digital stamp and signature on your invoices in QuickBooks Online (QBO).
You can utilize the Attachments field on your invoice to add your company's digital stamp and signature.
Here’s how:
Go to +New and select Invoice.
Fill in all the necessary information.
Scroll to the bottom of the invoice page.
In the Attachments field, click Add Attachment to select your digital company stamp and signature files.
Furthermore, if you're referring to customizing the invoice page to add the two, you may consider exploring third-party applications that allow you to attach these features.