To make the Gmail app open links in Safari, follow these steps:
1. Open the Gmail app on your device.
2. Tap on the menu button (three horizontal lines) in the top-left corner of the screen.
3. Scroll down and tap on "Settings".
4. Select your account from the list.
5. Under the "General" section, tap on "Default apps".
6. Tap on "Browser app".
7. Choose "Safari" from the list of available browsers.
8. Close the Settings menu. Now, when you tap on a link in the Gmail app, it will open in Safari.