Can this be used on <21 SDK?

[c0dehunter]

When adding to gradle, I am getting

Manifest merger failed : uses-sdk:minSdkVersion 19 cannot be smaller than version 21 declared in library [io.alterac.blurkit:blurkit:1.1.0] C:\Users\Lenovo.gradle\caches\transforms-2\files-2.1\88f728b8eb4a716869953bdefdd45c9b\AndroidManifest.xml as the library might be using APIs not available in 19 Suggestion: use a compatible library with a minSdk of at most 19, or increase this project's minSdk version to at least 21, or use tools:overrideLibrary="io.alterac.blurkit" to force usage (may lead to runtime failures)

Project's minSdk is 19.