Most Android phones can share mobile data by Wi-Fi, Bluetooth or USB.
Important: Some mobile operators limit or charge extra for tethering. We recommend checking with your operator.
Tether by Wi-Fi hotspot Step 1: Turn on your phone's hotspot
- Open your phone's Settings app.
- Tap Network and Internet Hotspot and tethering Wi-Fi hotspot.
- Turn on Wi-Fi hotspot.
- To see or change a hotspot setting, such as the name or password, tap it. If needed, first tap Set up Wi-Fi hotspot.
https://support.google.com/android/answer/9059108?hl=en-GB
So if it's the first one then you ARE using data.