To add Gmail to your iPhone and access your Gmail account through the Mail app, you can follow these steps:

1. Unlock your iPhone and go to the home screen.
2. Tap on the “Settings” app, which is represented by a gear icon.
3. In the Settings menu, scroll down and select “Mail.”
4. Tap on “Accounts.”
5. On the Accounts screen, tap on “Add Account.”
6. You’ll see a list of available email providers. Tap on “Google.”
7. Enter your Gmail email address in the provided field and tap “Next.”
8. Enter your Gmail password and tap “Next” again.
9. The Mail app will verify your account information, and you’ll be presented with a list of services you can enable. Toggle on the options you want to sync with your iPhone (Mail, Contacts, Calendars, etc.).
10. Tap “Save” to add your Gmail account to the Mail app.

After completing these steps, your Gmail account will be added to the Mail app on your iPhone. You can access your Gmail emails, send new emails, and manage your account directly through the Mail app.

Additionally, you can customize your email settings by going to “Settings” > “Mail” > “Accounts” > “Gmail” and selecting the desired options, such as sync frequency, notifications, and mailbox behaviors.

Remember that these instructions are specific to adding a Gmail account to the default Mail app on an iPhone. If you prefer to use the official Gmail app or a different email client, the setup process may differ.