As of Cloud Canary 2.2.2, you can upload custom files to both your Canary Windows File Share, or your Canary web server. To use this feature you'll need to connect from your workstation to the Cloud bird either on port 445 or port 80 (depending on which service you are configuring). In the remote upload process you'll be shown a link to your bird's public IP address (if present), as well as the private (internal) IP address as a second option.
Cloud configuration vary widely, but oftentimes Cloud birds are not Internet-accessible. In order to connect to your Cloud bird, you may need to add rules to your security groups to permit access to the Canary from your workstation, or configure something like AWS's VPN connections to your VPC.