This is a frequent issue lately ever since we made this change back in Nov 2023.
"API interactive Documentation update
Improved security by providing test keys to run request against the API and restricting user sensitive API keys to be pasted in the documentation."
The default API key is for a sandbox environment Org
For example this call works https://developer.cisco.com/meraki/api-v1/get-organizations/ because it simply returns the Org the API key has access to.
"id": "1215707",
"name": "API Demo Organization"
But when you run other endpoints that specify an Org, networks, etc that API key of course wouldn't work in your own Org. So, as @bbyw mentioned you need to add your API key if you want to use the dev site against your own Org.
One more example using the get Org networks call. If you put your Org ID in it will produce a 404 error because the default API doesn't have access to your Org. If you instead used the demo Org ID mentioned above 1215707 the call works as expected.
Ryan If you found this post helpful, please give it
Kudos. If my answer solves your problem please click
Accept as Solution so others can benefit from it.