In this tutorial we will figure out how to get Youtube API Key.
Follow steps below to obtain Youtube API key:
Step 1 : Go to Google Developer Platform Console
Step 2 : Open an existing project or create a new one
Step 3 : Click on Api & Services

Step 4 : Click on Library

Step 5 : Enter Youtube keyword

Step 6 : Click on Youtube Api Data V3

Step 7 : Click Enable

Step 8 : You will be redirected to Youtube API panel. You can see information about requests, logs, configure credentials or disable this API

Step 9 : Go to Credentials, then Create Credentials and choose API Key

Step 10 : A modal window with API key will open

Now this key is available in the API keys list

If you want:
you need to click on Restrict key link

Here you can see all configurations for your Youtube API key

If you opened a GDP project that created by Firebase, you can find already existing Youtube API key
