1) You should go to https://console.developers.google.com/project
then click on create new project, choose a name for the project then click create
2) When the project is created open it, then on the left sidebar click on the “Credentials” button under the “API & Auth” tab
3) In the credentials view you should be prompted to “Add Credentials”, then choose “API Key” from the credentials typology picklist
4) Now you should be prompted to choose the device type, that in our case is “Browser Key”
5) When confirmed you will be prompted to limit this key to only one domain (optional), then click on the create button, that’s it, you will see your new API key here.