How to disable save passwords on the iphone simulator ios 18

I'm running automated tests using selenium, appium and safari on ios simulators.

When my test logs in to a website, then safari opens a dialog that asks if you want to save the password.

This interrupts the test, so I want to disable that dialog. I never want to save the password in my tests.

Disabling password autofill used to also turn off this dialog. At least in ios 16.4 that was true.

But In ios 18 the dialog is still presented, even if password auto fill is disabled.

Ideally I need to know which settings to change in which plists.

But I can't even find a setting in the UI to turn it off.