Hello @Mlsmith1, welcome to the Seller Community!
Once an invoice is sent, you're not able to edit the email address that it was sent to.
However, you can edit your customers email address in their Customer Profile so that it's correct for future invoices.
An easy way to re-send an invoice that was sent to a typo'd email address is to use the "Duplicate" feature and enter the correct customer information.
Here's a screenshot for reference:
