Create account or log in if you are already a registered user.
Click on 'Add New App' on the screen window.
You need to Create certificate or key ID for the IOS and Android.
SETUP android FCM key click here.
SETUP IOS certificate for push click here.
Once new app setup successfully, click on the newly created app and go to app-setting where you will find one signal app-id in keys/ids section.
find more details about App ID and Rest API Key Click here
Save Detail in Notepad File.