The sketch is always "app/app.ino"

[formulahendry]

Actual:
I did not find a straightforward way to change the setting of sketch in arduino.json. I could only open the arduino.json and change the setting.

Expect:
Provide a straightforward way to change sketch setting. Maybe like Select Serial Port: provide a list of *.ino files for users to select

[robotdad]

This is also at the root of issues with verify and deploy. I opened a sketch of any name and the arduino.json always says app/app.ino. When you change that to match the .ino name in your folder verify/deploy work.

[yaohaizh]

This is defined behavior by Arduino IDE. It has to be an entry ino/cpp file for build