It would be nice to provide a suggested workaround if it is impractical to update examples (ideally 0.15 and onward compatible.
e.g.
#Find and download latest compatible 0.12.x version and alias it (as opposed to install since you probably don't want an old binary, when you start your own build out)
https://releases.hashicorp.com/terraform/
alias terraform=/Users/mpatters/bin/terraform-0.12.30
terraform -version
Terraform v0.12.30
+ provider.aws v2.70.0
brew install terraform
0.14.7
versionrequired_version = ">= 0.12, < 0.13"
e.g.