@JPC6892 the link that @alemabrahao posted is to the documentation and test page for use by humans, it's not the actual endpoint as it would used for real (which is like... https://api.meraki.com/api/v1/organizations/org_id/apiRequests )
In practice you need to access this endpoint within a program that has the surrounding code to handle scheduling, authentication etc., get the data and then push it to your SIEM tool.
Meraki make the API available, they don't generally develop integrations for other companies' tools - that's the job of the SIEM developer, third-party developer(s), or you/your organization to do.
Afaik there's no Meraki webhook (or other push) of the API usage data, so the only way you'll get it is via the API.
If you want to detect in near real-time, you need to develop something to get the last few minutes usage data every few minutes, then push it into your SIEM using whatever method it supports.
If you know Python, the Meraki Python library simplifies using the API... https://github.com/meraki/dashboard-api-python