Hello @LisaF1385 ...
It does look like the Nearpod LTI external app does require a Consumer Key and Shared Secret. Here's a page on the EduAppCenter that should be of help to you. There's a link to generate the Consumer Key and Shared Secret on that page. I'm not sure if there is any cost for this product, though.
I hope this will help a bit, Lisa. Sing out if you have any other questions...thanks! Take care, stay safe, and be well.