Prerequisites

1. You have administrative privileges to register new apps in your Azure Active Directory.
2. The Salesforce administrator has provided you with the Redirect URI. 

Steps

Register App with Azure Active Directory

Follow the link below to create a new registration for sFiles. 
https://portal.azure.com/#blade/Microsoft_AAD_IAM/ActiveDirectoryMenuBlade/RegisteredApps

1. Click New Registration.
2. Give the app a relevant name like sFiles.
3. Select Accounts in this organizational directory only for account type.
4. For your Redirect URI, paste the Redirect URI sent to you by the Salesforce administrator.
5. The Redirect URI should look something like: https://mycompany.my.salesforce.com/services/authcallback/sFilesProvider

Generate Secret

Once the registration is complete, you will need to generate a secret key to use between Salesforce and Azure to control the OAuth process.  Please follow the instructions here -> Create a new Azure Application Client Secret
 

Grant Permissions

Navigate to API permissions and click Add a permission.
Select Microsoft Graph and then select Delegated permissions. Add the following: Click Add Permissions.
Your permissions should look like the following:

Send IDs and Secret back to Salesforce Admin

Send the following information to the Salesforce administrator:

1. Application (client) ID
2. Directory (tenant) ID
3. Client secret