IAP issue with unity 2019 version

Hello I’m using unity 2019.2.0b2.

When I import the in app purchase package. I’m getting following errors.

Assets\Plugins\UnityPurchasing\script\IAPDemo.cs(20,19): error CS0234: The type or namespace name ‘Store’ does not exist in the namespace ‘UnityEngine’ (are you missing an assembly reference?)
Assets\Plugins\UnityPurchasing\script\IAPDemo.cs(630,38): error CS0246: The type or namespace name ‘ILoginListener’ could not be found (are you missing a using directive or an assembly reference?)
Assets\Plugins\UnityPurchasing\script\IAPDemo.cs(647,29): error CS0246: The type or namespace name ‘UserInfo’ could not be found (are you missing a using directive or an assembly reference?)
Assets\Plugins\UnityPurchasing\script\IAPDemo.cs(634,25): error CS0246: The type or namespace name ‘UserInfo’ could not be found (are you missing a using directive or an assembly reference?)

I have attached the screenshot of it.

Please help me out. TIA

I have the same errors in the log, any solutions??