Android app made in Unity – We need some help to solve a communication issue

We have an Android app developed in Unity, and we want it to communicate with a feature developed in Android Studio. To be more specific, we have to create a call from Unity that will activate the Android Studio code. Skills required: Unity, Android Studio.
Unity side has to be able to send a variable, like a string to the android side, which has been previously exported from this same Unity project, using the ‘export to Android Studio’s button.
The project is about creating a parental control app that is linked to an educational app delivering homework assignments from schoolteachers to students. Parents have the option to lock their kids’ devices until homework is completed. When homework is completed, the lock function is automatically lifted, so the kids can access games and other apps. What we are trying to fix now is the communication between the edu app (Unity) and the control app (Android Studio).
Please only reply if you have expertise in Unity, Android Studio and possibly Kotlin.