SDK location not found. Define location with an ANDROID_SDK_ROOT environment variable or by setting the sdk.dir
1. Go to your Project -> Android
2. Create a file local.properties
3. Open the file
4. Paste your Android SDK path depending on the operating system:
4.a Windows
sdk.dir = C:/Users/USERNAME/AppData/Local/Android/sdk
4.b Linux or MacOS
sdk.dir = /home/USERNAME/Android/sdk
Replace USERNAME with your user name