Cannot read property "initialize" of undefined

Hi, I’ve tried to implement the initialization of the sdk with react native app but I get the error stating “Cannot read property ‘initialize’ of undefined” I’ve already got the app id and token from the cloud.

Anything I missed out? is there a more sequential documentation about the beacon setup?

RNEstimoteProximity.initialize(
      Object.assign({}, config, {
        appId: credentials.appId,
        appToken: credentials.appToken
      })
    );

Is not a valid function. Console.log(RNEstimoteProximity) gives me undefined. Any sugestion?