After purchase, you must register the license in the AnyDesk クライアント.
You can do that either by signing in, which automatically registers the license, or by copying the ライセンスキー from my.anydesk and pasting it into AnyDesk > Change License Key > Register license key.
On Windows with AnyDesk 9.0.0 or later, you can also register directly from my.anydesk II.