Hi Gcobani,
Greetings from Syncfusion Support..!
We have validated your shared link and shared snippets at our end and you have enabled the readonly property of the Scheduler, in that case we can’t perform CRUD actions. We suspect that, your requirement is to customize a CRUD sample for scheduler and for that, kindly refer to the following sample.
Note: In our Remote data sample, we have only retrieved the data from remote and made the scheduler readonly.
Kindly try the above UG links and get back to us if you need any further assistance.
Regards,
Nevitha