See explanation below.
Explanation
Go to the Microsoft 365 admin center and then click .
Select Pradeep Gupta.
On the properties flyout page, click the More actions, click Manage litigation hold.
Graphical user interface, application Description automatically generated

On the Manage litigation hold flyout page, select the Turn on litigation hold checkbox and then enter the following optional information:
Hold duration (days): Use this box to create a time-based hold and specify how long mailbox items are held when the mailbox is placed on Litigation hold. The duration is calculated from the date a mailbox item is received or created. When the hold duration expires for a specific item, that item will no longer be preserved.
If you leave this box blank, items are preserved indefinitely or until the hold is removed. Configure 90 days.


Note visible to the user: Use this box to inform the user their mailbox is on Litigation hold. The note will appear on the Account Information page in the user's mailbox if they're using Outlook 2010 or later. To access this page, users can click File in Outlook.


Web page with more information for the user: Use this box to direct the user to a website for more information about Litigation hold. This URL appears on the Account Information page in the user's mailbox if they are using Outlook 2010 or later. To access this page, users can click File in Outlook.


Click Save changes on the Litigation hold flyout page to create the hold.
The system displays a banner saying it might take up to 240 minutes for the change to take effect.
Reference:
https://docs.microsoft.com/en-us/microsoft-365/compliance/create-a-litigation-hold?view=o365-worldwide