There are two ways you can approve and reject hours. You can do it in bulk or one submission at a time.
Start off by going to your Organizer Dashboard
Click on the Approvals Tab
Approve/Verify in Bulk
Check all the names that apply
In the "Action" dropdown, select Approve Hours or Reject Hours, then click on Run.
Click on Confirm to continue the process, or Cancel to move back.
Approve/Reject one submission at a time
Click on the "+" sign next to the volunteers name
Then click on Review Log
After reviewing the details, click on the green Approve button to approve the submission or provide a reason in the text box and click the red Reject & Send button to reject the submission.
For more help with the Verification Dashboard, see this article.