Null object reference on customization setButtonBackVisible(true);

[Apsalogics]

Attempt to invoke virtual method 'void android.widget.ImageButton.setVisibility(int)' on a null object reference
This issue is raised on Huawei Device
This issue raised when customization start
https://github.com/heinrichreimer/material-intro#customization

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageButton.setVisibility(int)' on a null object reference
at com.heinrichreimersoftware.materialintro.app.IntroActivity.setButtonBackVisible(IntroActivity.java:1149)
at Pakigname.Activityname.onCreate(Activityname.java:24)
at android.app.Activity.performCreate(Activity.java:7383)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1218)