In Microsoft Dynamics 365 Business Central, the endpoint URL for a custom API page follows a strictly defined hierarchical structure. After the environment and the /api/ segment, the URI must include three segments to identify the specific API: APIPublisher, APIGroup, and APIVersion. These correspond to the properties defined in the AL language for the API page object. Finally, after the company identification, the EntitySetName (which is usually the pluralized name of the entity, such as "rooms") is used to access the specific resource. Following standard naming conventions for the "RoomsAPI" page, the publisher is alpine, the group is integration, the version is v2.0, and the entity set is rooms.

Microsoft Learn: Create a custom API in Business Central. Section: "API properties". (URL: https://learn.microsoft.com/en-us/dynamics365/business-central/dev-itpro/developer/devenv-api-pagetype)

Microsoft Documentation: Developing Connect Apps for Dynamics 365 Business Central. Section: "Endpoints for APIs".

Microsoft Learn: Work with the API in Business Central. Section: "Custom APIs".

AL Language Reference: Page Object Properties - APIPublisher, APIGroup, APIVersion, EntitySetName. (Microsoft Dynamics 365 Business Central Developer Documentation).