Same gateway for different environment(s)

Hello here,

I am really new and tried to create my first lambda for AWS; requirements were that we have different stages (dev, qa, prod)
when everything was created and deployed, I had noticed that for AWS API Gateway,
i have a new gateway for each environment… something like this:
https://blahblah.execute-api.us-west-2.amazonaws.com/dev/
https://different.string.execute-api.us-west-2.amazonaws.com/qa/
and etc…

my goal is actually to have 1 unique api
https://<blah.blah.blah>.execute-api.us-west-2.amazonaws.com/{dev|qa|prod}/

where we would have 1 gateway pointed to different environments, but I could not find any examples how to do that.
Any idea?
thank you

I found a good article regarding this issue and why serverless works that way. Maybe it can help you.