Google Pixel 8a
It's not possible to use my phone's internet connection
Solution 3 of 4: Data roaming is turned off
You can limit your data usage when abroad by turning off data roaming. You'll then not be able to access the internet using the mobile network when abroad. You can still use Wi-Fi even though data roaming is turned off.
Slide two fingers downwards starting from the top of the screen.
Press the settings icon.
Press Network and Internet.
Press SIMs.
Press the name of the SIM.
Press the indicator next to "Roaming" to turn the function on or off.
Slide your finger upwards starting from the bottom of the screen to return to the home screen.