How do I generate Google content API for shopping keys? Docs are outdated

Question

I've made it about 2 steps through the Google content API docs where they are instructing me to generate keys within merchant center. Here are the instructions:

To download your service account credentials, complete the following steps:

In Merchant Center, in the Settings menu, select Content API. Click Authentication. Click [+] CREATE API KEY. If prompted, read and accept the terms of service agreements. The new key downloads automatically.

I've clicked through all of the links available in the merchant center dashboard, but can't find anything alluding to keys for the content API. No video tutorials from this decade seem to be available. I'm really stuck here!