Open APIs section of the API Gateway console.
In the list of the APIs, click on the name of the API (UsersAPI).
You will be redirected to the Resources section of the UsersAPI.
Click Deploy API

*New stage*.dev.Deploy.
Stages page of UsersAPI.Invoke URL of dev stage.
Congratulations, you have deployed an API Gateway. Copy the invoke URL of the dev stage, you will need it in the next step.