You can preview your 1040 to see where the credit is coming from.
When logged in to your account, on the Tax Home page,
1. Click Review/Edit or Pick up where you left off on any of the tax return topics
2. Once completely in your return, click on Tax Tools on the left hand panel (you may have to scroll down)
3. Click Tools
4. Click View Tax Summary on the pop up menu
5. On the left hand panel, click Preview my 1040
You may need to scroll down to the Schedule 3 to see where that credit came from.