Happy New Year! Can you please let us know your use case and what it is that you're trying to do?
Here are links to some B2B APIs for you to take a look at.
B2B Virtual Account Payment Method
B2B VAPM Overview - https://developer.visa.com/capabilities/vpa
B2B VAPM Docs - https://developer.visa.com/capabilities/vpa/docs-getting-started
Visa B2B Connect
B2B Connect Overview - https://developer.visa.com/capabilities/vba
B2B Connect Docs - https://developer.visa.com/capabilities/vba/docs-getting-started
To get started, please look at our website for specific APIs that would be a good fit for your use case.
Then follow the steps in the “Working with Visa APIs” link below to register and create a Visa Developer application.
The Working with Visa APIs guide shows you the key steps for application creation, credentials, and connection validation.
After testing your App in sandbox, submit a Going Live request for evaluation.
Besides the steps above on how to get started, it looks like you're on the right track with asking your questions here in the Visa Developer Center community forum. You can also email your questions to firstname.lastname@example.org. Both of these channels have dedicated Visa Developer support staff that will be happy to help answer your questions.
Was your question answered? Don't forget to click on "Accept as Solution" to help other devs find the answer to the same question.