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Go to Setup > Profile > Standard Platform User / Standard Platform One App User / Standard Platform User > Object Settings > My Calendar > Default On > Save.
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Note: You need to configure the Profile of the User that you want to give access to My Calendar.
In the Standard Platform One App User profile, go to the Apex Class Access and the following Apex Classes
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To check if the component is working, go to Setup > Users > Look for the staff member (Ex. Michael Aitken) > click Login.
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