Graph API SDK

The client I am working for has a mvc app called Dairy inside and dynamics CRM. I am a CRM developer. So when click on the dairy it opens a new mvc where they it shows the calendar to create events and there is a button called outlook. When clicked on it shows the outlooks events or appointments and if I click on the same button it hides the outlook appointments back.This is the current functionality but once the user account. Is migrated to cloud it stopped working as there is no code written for exchnage online users. So the client wanted to have a graph api approach to call the exchange user calendar events and show in the same dairy app. I have no clue how to work on it and have a dead line by Tuesday. I didn’t get help from any in my work and even if they give they are not proven and faintly failed. Would u be able to help me