For registration you need to fill out the electronic form at https://developers.vub.sk.
After completing and submitting the form, you will be contacted by a VÚB bank employee who will require a document from you, signed with your EV certificate. You will use this certificate to create a secure Mutual TLS (Transport Layer Security) connection for access to VÚB API. The certificate is proof that you are authorized to act on behalf of another payment service provider (third party).
Your company will then be verified against the National Bank of Slovakia (NBS) registry. After successful verification, you as a developer and your company will be registered on the Developer Portal. At the same time, you will receive an OAUTH2 ClientID and ClientSecret and you can start using the API. In order to use the API, it is necessary to request the subscription of specific APIs through the Developer Portal.