Add the SharePoint site.
From the navigation pane, go to Protect > Applications > Office 365.
The Office 365 apps page appears.
Click Add Office 365 app, and then select SharePoint Online (Classic).
The SharePoint Online page appears.
In the Name box, enter a name for the app.
From the Server plan list, select the server backup plan to use for the site.
From the Access node list, select a proxy computer that has SharePoint agent installed.
Before selecting the access node, verify that you already provided the service account information on the proxy computer.
In the Tenant admin site URL box, type the URL for the tenant admin site.
For example, enter https://office_365_tenant_prefix-admin.sharepoint.com.
To enable modern authentication during backups and restores, move the Use modern authentication toggle key to the right. Provide the following information:
In the Application ID box, type the application ID.
In the Application secret box, type the key value.
In the Azure directory ID box, type the directory ID.
Note: For information about obtaining the application ID, the Azure directory ID, and the application key value, see Registering the Azure App for SharePoint Online.
Type your login credentials for the SharePoint online administrator user account that can connect to the tenant, and that is also the site collection administrator.
If you have two-factor authentication enabled, generate an app password and use the app password to connect to the tenant.
In the Azure storage user account box, enter an Azure storage account.
In the Azure storage account key box, type the primary or the secondary account key.