On Catappult's dashboard, you can add the In-App Products manually as show bellow.
When editing a product you can set the retail price for each currency. If the retail price for a specific currency is not specified, the charged amount for such currencies will be automatically converted from the reference price at the moment of purchase. You can flag a price as a reference when editing any price, but you won't be able to delete a flagged price.
To upload the products to Catappult, you can use a CSV file (exported from Google Play) or add each product manually.
In-App Products can also be set automatically, if the app went through an automatic migration process. Therefore, Catappult can fetch out the products and prices currently being sold at USD price, without any manual action.
Nevertheless, the automatic In-App Products does not allow to differentiate prices between countries for the same product. Prices worldwide will be based on the current USD price.
Updated 3 days ago