As an update, after repeatedly speed-dialing customer service, I managed to get in a queue to wait on hold. After about 25 minutes, I spoke to a customer service rep who managed to enter in all our API. I asked him why I couldn't do it myself online and he said it just happens sometimes 🤷‍♂️ I was able to view the API online after the call and edit it. Good to know that I would have been able to provide the API as part of the online check in process.