SEPA
SEPA Direct Debit is a pull based and asynchronous payment method. Once given a mandate by your customer it is you who initiates the payment. Following this, there is usually a delay between 2-5 business days before the payment is actually settled.
You can capture the authorized amount in a single API request as depicted in the payment flow below.

API Capture Request and Response
The previously authorized transaction is identified by the "uniqueReference". Set at most the same amount as initially authorized under the "modifiedAmount" parameter in the API method 1.29 Capture.