Is it possible to change the amount for an authorization, after the request is sent?

Unfortunately no, because the customer has only given you permission to authorize for a specific amount. If you would like to change the amount for authorization, you need to create a new authorization request for the updated amount.

The only things that can be updated in an authorization request are the description and the customer details for receipt such as SMS or email.

You can have a more detailed look at our authorize API within our documentation page and create an authorization request yourself to view the response.