Welcome to the Q&A English version forum.
Through translation tool, I find you need to migrate data from Microsoft OneDrive to Ionos OneDrive.
As far as I know, Microsoft has migration tools, but they all migrate content to Microsoft OneDrive. For more, please refer to: Migrate your content to Microsoft 365.
However, since we do not have a test environment for this Ionos OneDrive product, we cannot promise you that the tools listed in the document are suitable for you.
Thanks for your understanding.