Hello there, jmogalian.
Upon further review, it looks like you've already posted the same question here in the Community, and my colleague already provided you with an answer.
Please refer to this link for more information: https://quickbooks.intuit.com/learn-support/en-us/payments/re-how-do-i-add-a-signature-to-the-checks....
I'll be around if you need additional assistance with personalizing checks or any QuickBooks-related queries. We're glad to help. Take care.