Sometimes you want to charge a user a custom amount that is not covered by your existing collection of products, memberships and credit packs. It's possible to create a custom charge product to cover these cases.
Create a 'custom charge' product
To create a 'custom charge' product:
Go to Settings > Products > + Product.
Name the new product 'custom charge' (or similar).
Disable the Available Online toggle (so that users don't see the custom charge in the shop or on your website).
Set the price and then select Create.