Hello,
Basically SchedulerPro data classes extend Engine classes which provide smart logic to the Scheduler and calculate tasks start/end dates, duration, etc. Please read the following guides:
https://www.bryntum.com/docs/scheduler-pro/#guides/schedulerpro/getting_started.md
https://www.bryntum.com/docs/scheduler-pro/#guides/schedulerpro/project_data.md
And there is a link to "Scheduling Engine API docs" on the left: https://www.bryntum.com/docs/scheduler-pro/engine/
If you're using a lib/framework, for example React, you can see in our docs we're using Scheduler Engine terminology. That's is because we have a wrapper per framework, and to get native Scheduler instance users can access it through a property, for example this.schedulerInstance. https://www.bryntum.com/docs/scheduler-pro/#guides/integration/react.md#the-native-bryntum-scheduler-instance
Please go through our examples to get some inspiration: https://www.bryntum.com/examples/scheduler-pro/
If you have any further questions, please create a new thread and provide all details as described in this guide: viewtopic.php?f=35&t=772
Cheers!