To obtain the Agora API Key for live-streaming, you need to follow these steps:

1. Firstly, visit the website of the Agora API provider at https://console.agora.io/.

2. Then, create an account or log in if you have already and account.

3. Once you've logged in, go to the Project Management side menu, and click on the “configure” button in the table data.

4. Then, You will be redirected to the project editing page, where you can find the App ID and App certificate key.