All data in the SharePoint Online are stored in the Microsoft cloud. It is not possible to change the storage location of SharePoint online.
Per my research, there are two ways to increase the storage for SharePoint.
1.The first way is to increase the storage of OneDrive.
For most subscription plans, the default storage space for each user's OneDrive is 1 TB. Depending on your plan and the number of licensed users, you can increase this storage up to 5 TB.
Go to SharePoint admin center -> Settings -> OneDrive Storage limit -> Set the default storage amount.
And if one of users reaches the 5 TB limit, then open a contact support with Microsoft to discuss your needs, may could increase to 25 TB.
https://learn.microsoft.com/en-us/sharepoint/set-default-storage-space
2.The second way is to increase the storage of SharePoint.
Go to Microsoft 365 admin center to buy the Office 365 Extra File Storage add-on.
https://learn.microsoft.com/en-us/microsoft-365/commerce/add-storage-space?view=o365-worldwide
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