Just d/led Bumblebee and wanting to upgrade an existing Android Studio Kotlin/Android project. But it says this is not a Gradle-based project? any help, please

What version of AGP are you on?

7.0.2-bin

That's likely your gradle version. What version of the android gradle plugin though? e.g.

"com.android.tools.build:gradle:7.1.0-alpha02"

Likely in your root build.gradle

yes, classpath("com.android.tools.buildG7.1.0-alpha02")

No idea then. Looks like it's up to date.

One small (not too hot tip). Do never update your AS, but do rather download it manually, unblock (!! that may be a reason in windows environments, beacause of some obscure things around file access), unpack, and cut -> paste to the destination directory. and rename the directory to a common name for yourself like (Android Studio 2021.1.1.2), you then have the ability to use the old version if it doesn't work (in some circumstances you can still use the newer AGP version...) Check File->Project structure