I just joined today.I never understand how to create virtual card.can anyone explain
the best place to start would be to check out the docs site that gives a virtual card overview and guide. Hope this helps. https://www.marqeta.com/docs/core-api/cards
Adding to the already existing comment. If you follow the steps here: https://www.marqeta.com/docs/developer-guides/core-api-quick-start#_step_1_create_assets it will walk you through the set of API calls to then create a card.