When, I am trying to Run Code Then Showing Error

Hey, Friends
On Android Studio I have created one application but when I am trying to run my app then showing Three Errors -> 1. Caused by: org.gradle.api.internal.artifacts.ivyservice.DefaultLenientConfiguration$ArtifactResolveException: Could not resolve all artifacts for configuration ‘:classpath’.
2.Caused by: org.gradle.internal.resolve.ModuleVersionResolveException: Could not resolve com.android.tools.build:gradle:3.6.3.
3.Caused by: org.gradle.internal.resolve.ModuleVersionResolveException: No cached version of com.android.tools.build:gradle:3.6.3 available for offline mode.

FAILURE: Build failed with an exception.

  • What went wrong:
    A problem occurred configuring root project ‘MostUsedMachine’.

Could not resolve all artifacts for configuration ‘:classpath’.
Could not resolve com.android.tools.build:gradle:3.6.3.
Required by:
project :
No cached version of com.android.tools.build:gradle:3.6.3 available for offline mode.
No cached version of com.android.tools.build:gradle:3.6.3 available for offline mode.

  • Try:
    Run with --stacktrace option to get the stack trace. Run with --debug option to get more log output. Run with --scan to get full insights.

  • Get more help at https://help.gradle.org

BUILD FAILED in 67ms

Please tell me how to solve this Error