a. Create a project in the Google Developers Console. For example, create a project callediNotes Calendar.
b. Search the Google API Library to find the Google Calendar API. Select it and clickEnable.
c. Click Credentials -> Create credentials -> API key.
d. After the API key is created, click Restrict key.
e. Add a name, select HTTP referrers, and add the mail server information. ClickSave.
f. Return to the Credentials page. Click Create credentials -> OAuth Client ID.
g. Select Web application from the Application type list, add a name, and the mail server information. Click Create.