You can only capture signatures using the QuickBooks Online app, Bret-troxell.

It lets your customers sign an estimate or invoice for a fast and secure transaction.

First, download the app from the Google store or App store. 

Then, when creating an estimate or invoice, you can get their signature. I'll share with you the article with the steps depending on what phone (iOS and Android) you're using.

Although, if you wish to use your signature pad, you can check for third-party apps that will help you capture the signatures. Visit our Apps website for the list. 

Reach out to us again if you need our help. We're just around to assist you.