Update requirements-for-listing-an-app.md (typo fix)

Author: SwuduSusuwu

content/apps/github-marketplace/creating-apps-for-github-marketplace/requirements-for-listing-an-app.md

@@ -91,7 +91,7 @@ When you are ready to publish the app on {% data variables.product.prodname_mark
 
 ## Billing requirements for paid apps
 
-Your app does not need to handle payments but does need to use {% data variables.product.prodname_marketplace %} purchase events to manage new purchases, upgrades, downgrades, cancellations, and free trials. For information about how integrate these events into your app, see [AUTOTITLE](/apps/github-marketplace/using-the-github-marketplace-api-in-your-app).
+Your app does not need to handle payments but does need to use {% data variables.product.prodname_marketplace %} purchase events to manage new purchases, upgrades, downgrades, cancellations, and free trials. For information about how to integrate these events into your app, see [AUTOTITLE](/apps/github-marketplace/using-the-github-marketplace-api-in-your-app).
 
 Using {% data variables.product.github %}'s billing API allows customers to purchase an app without leaving {% data variables.product.github %} and to pay for the service with the payment method already attached to their account on {% data variables.product.github %}.