Get Users Outlook Meetings via API using Graph API.

Step 1 : Get Access Token
Step 2 : Set up URL and request body in POSTMAN

Step 1 : To get Access token, Visit my blog here

There are many API exposed by Microsoft for Microsoft 365 data,
Microsoft Doc

Step 2 : Open POSTMAN
Add Request to collection,

URL : https://graph.microsoft.com/beta//users/andrewr@test.onmicrosoft.com/calendar/getSchedule

Go to Authorization > Paste the token which we get from Step 1

{        
    "schedules": ["adelev@contoso.onmicrosoft.com", "meganb@contoso.onmicrosoft.com"],
    "startTime": {
        "dateTime": "2019-03-15T09:00:00",
        "timeZone": "Pacific Standard Time"
    },
    "endTime": {
        "dateTime": "2019-03-15T18:00:00",
        "timeZone": "Pacific Standard Time"
    },
    "availabilityViewInterval": 60
}

Click Send and you must get following response.

For more API’s and other options, follow microsoft document.

Just change and URL and body.

https://docs.microsoft.com/en-us/graph/overview?view=graph-rest-beta

There is so many details you can get about Specific use, via API,

Note : you must have access in azure defined