Possibility to open flexfields in the payment process request

Summary:

Dear all,
We would like to ask for information about the possibility of opening DFFs on the Payment Process Request page.
Specifically, when creating the Payment Process Request, the customer requested that information be entered that is not included in the standard fields. However, we are unable to create these fields. Is there a workaround? Is it not possible?

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

25B (11.13.25.04.0)

Code Snippet (add any code snippets that support your topic, if applicable):