Why am I unable to find these provider versions?

Hi, I'm trying to create a sample/POC to see if I can create an AWS configuration with two different provider versions and pass that to my module hierarchy.

https://github.com/qzhang1/Terraform-Multi-Provider-Example

But on Terraform init I get this error:

Initializing provider plugins...
- Finding hashicorp/aws versions matching "<= 4.16.*, 3.55.*, 4.16.*"...

Error: Failed to query available provider packages

Could not retrieve the list of available versions for provider hashicorp/aws:
no available releases match the given constraints <= 4.16.*, 3.55.*, 4.16.*

Can someone more experienced please tell me why this is?