Where is airplane mode on the Apple Watch with newest updates

Use Control Center on Apple Watch describes how to use the new steps to get to the Control Center:

Open or close Control Center

• Open Control Center: Press the side button once.
• Close Control Center: With Control Center open, turn your wrist away from you or press the side button again.

You may also want to...

Rearrange Control Center

You can rearrange the buttons in Control Center by following these steps:

1. Press the side button to open Control Center.
2. Scroll to the bottom of Control Center, then tap Edit.
3. Touch and hold a button, then drag it to a new location.
4. Tap Done when you’re finished.