What did you do so far?
Created an profile and you want to download it? Sent the link by mail and then this happens?
easiest way is try enrolling using QR Code from within the Network --> Systems Manager --> Devices
But what exactly to you want to do. Have you any authentication Setting activated? Which OS?
@aokullu Are trying to enroll using MDM profile or Meraki Agent? both of them are pretty easy to enroll in their own ways. For profile installation there are multiple ways to install, you can scan the QR code or go to m.meraki.com and enroll using the network shown on the dashboard. If you are new to Meraki systems manager, please go through this document, it is really helpful, will give you the full picture.