However, the side of CloudFormation template doesn't have it yet.
$ awsdac https://raw.githubusercontent.com/awslabs/diagram-as-code/main/examples/vpc-subnet-ec2-cfn.yaml --cfn-template
FATA[0000] unable to read file: open https://raw.githubusercontent.com/awslabs/diagram-as-code/main/examples/vpc-subnet-ec2-cfn.yaml: no such file or directory
exit status 1
Detail
Dac file (diagram as code format file) has already this feature, which allows you to describe a raw URL as an input file. PR: https://github.com/awslabs/diagram-as-code/pull/83
However, the side of CloudFormation template doesn't have it yet.