First, you have to check you are authorized to create a bucket or not.
Go TO IAM Roles https://console.aws.amazon.com/iam/home#/home
and check your policy summary
If you have access then go to https://console.aws.amazon.com/cloudformation/home?region=us-east-1#/stacks?filter=active
and search for slack defined in your ( for me it is: policy.cellbio-pringles-xtra-*)
remember your slack name always start with the string given on your policy.
Upload your file and create it.
now go to s3 and check your bucket is ready to use.
