Action scoped custom dimensions

Hey there! I’m looking to implement action-scoped custom dimensions with the events in the iOS SDK. The documentation says I can set visit-scoped custom dimensions in the SDK. https://github.com/matomo-org/matomo-sdk-ios#custom-dimension

Can we not set them using the SDK? If we want action-scoped ones, are we supposed to use the Tracking HTTP API? There are similar questions in the forum but no answers.