By default administrators don’t have access to any OneDrives.
However, it’s possible to grant access to the accounts of your choice using PowerShell.

This article shows you how to grant permissions using powershell.

Programmatically create an Administrator account for OneDrive (with PowerShell)

First, download and install the SharePoint Online CmdLets.

The script below adds an administrator account to all OneDrive users of a given domain.

Note:

This script is provided as is.
Cloudiway does not maintain this code nor provide support for it.