This is a project that sends mail from backend(nodejs) using nodemailer.
Step 1: Go to console.cloud.google.com
Step 2: Create new project
Add Project Name
Step 3: Select your project (if other projects are there)
Step 4: Select APIs and Services tab(Go to OAuth Concent screen)
Step 5: Choose external and create
Fill up:-
App name
User Support Email
Developer Contact Information(Your Email)
(Save and continue)
Step 6: Leave Scopes and Test Users tab as default and continue
Step 7: Click Back to Dashboard
Step 8: Now Go to Credential (Create Credentials (OAuth2 Cliend ID))
Step 9: Select Web Application on Application type and provide App Name
Step 11: Save client id and client secret
Step 12: Go to redirect URI
Step 13: Click on setting button on top right setting button
Step 14: Check Use your own OAuth credentials
Step 15: Paste credentials
Step 16: Go to redirect URI
Step 18: Continue with your gmail account
Step 19: If the app isn't verified then go to show advanced and click go to gmail apis
Step 20: Save refresh token