spacedesk connection over native android USB debugging is not supported.
As an alternative you can try either of the following:
– Android debug bridge cable (requires Android SDK installed on your primary machine)
– USB tethering connection (if you android tablet supports USB tethering)
For assistance, please check Performance tuning -> Network Bandwidth chapter in the user manual https://www.spacedesk.net/user-manual/.
By the way, we have moved your post to a new topic to avoid confusion.