The SDK must be configured with secret key before starting BearSDK usage.

try BearSDK.setSecretKey("key")

You have to call the BearSDK.setSecretKey("key") method using a secret key as parameter. You can check the sample app and use its secret key during your development cycle. However you have to use your own secret key before submitting your application to production (this secret key will be provided by ARGO).