Run through the prerequisites listed here
Get your device details; IP address, SSH username and password. Here's a handy checklist!
Create a dashboard account if you don't already have one.
Enable and grab your API Key.
Download and run the Catalyst onboarding app: Windows, MacOS, Linux
Now, your device(s) are ready in Dashboard!
Click on the link below for everything you need to know about Cloud Monitoring for Catalyst Switches!
Cloud Monitoring Resources
Sameh Sackla - Cisco Meraki