Hi @Artem1,
The Visa Checkout team does not accept direct merchant. You will need to work with a partner in order to integrate Visa Checkout into your project.
You can find the list of Partners to integrate with Visa Checkout here: https://globalcheckout.visa.com/visacheckoutPartners
Please note, partners handle integrations on their end and will be able to help you with any technical questions you have, due to the fact that, that they manage a different integration with our API and the Visa Developer Portal.