In App Billing Configuration For Unsupported Countries

Only certain countries are cleared for purchases using Google's Merchant system, which runs In App Billing.

If you are not able to have a Google Merchant account you must make the following change to your Manifest.

Locate this line:

<meta-data android:name="com.skillz.IAB_PUBLIC_KEY" android:value="null" />

Remove the entire line from the Manifest.  This will remove the In App Billing functions in Skillz. 

To find a list of supported countries for In App Billing see This Article.