JCenter has shutdown

[CarlAmko]

As of May 1, 2021, JCenter is no longer hosting artifacts.

Please migrate the artifacts to Maven Central or an alternate hosting location.

[CyxouD]

For now, you can add JCenter to your repositories in settings.gradle. Mine looks like this:

pluginManagement {
    repositories {
        gradlePluginPortal()
        google()
        mavenCentral()
    }
}
dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        google()
        mavenCentral()
        //noinspection JcenterRepositoryObsolete It is needed to add "com.dinuscxj.progressbar.CircleProgressBar" dependency which is available only at JCenter
        jcenter()
    }
}

// ....