You can use the same API key for multiple websites, or you can generate a new key for each site. You can generate up to 500 unique API keys.
Using a different API key for each site allows you to disable the key if you're no longer using it on an active website, or have stopped supporting the project. You can also add a label for each individual API Key so you can easily keep track of them.
We recommend that you keep a record of which API key is being used on each site.
NOTE: You can manage your API keys from Account -> Username & API Key -> API Keys: