Hi Mortjako
Thanks for reaching out.
ATUM works only on the same WC site. If you want to integrate several separate websites, you will need custom coding. Unfortunately, it is out of the scope of our service, so I'd kindly suggest you find a developer to achieve this.
With MI you can create as many inventories as you want within the same site (offline or online). But not handle data from other sites.
Best regards,
Iryna