To understand the cards acquisition API please refer to Introduction to Card Acquiring.
Please refer to this tutorial on how to add a card Tutorial: Acquiring Cards in MBanq Cloud API

Purpose: Use this API to add an acquired card for the client.

Browser SDK flow:

1. Call GET /v1/externalcards/configuration.
2. Load the TabaPay Browser SDK using sdkUrl.
3. Initialize the SDK using browserClientId.
4. Capture card information through the Browser SDK.
5. Receive a short-lived cardToken from the SDK.
6. Submit the token to POST /v1/clients/{clientId}/externalcards.
7. Read clientId and resourceId from the successful response.

Raw card information must be entered through the provider's Browser SDK
and must not be sent directly to the Mbanq API.

Behaviour: A successful response indicates that the acquired card was
added and contains only the client ID and the new acquired-card resource ID.