To find the project name manually, you can look in AndroidManifest.xml or in Info.plist.
Android
In Android the package name is in the AndroidManifest:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
...
package="com.example.appname">
iOS
In iOS the package name is the bundle identifier in Info.plist:
<key>CFBundleIdentifier</key>
<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
which is found in Runner.xcodeproj/project.pbxproj:
PRODUCT_BUNDLE_IDENTIFIER = com.example.appname;
See also
- How to change package name in flutter?