Here’s the answer I received from Accusonus support:
‘We recently announced changes to our product line. Any accounts containing Beat Making and Drum Mixing products, such as Regroover and drumatom, have been removed from our system. Therefore, no account will be found if you try to log-in to the website.
As a perpetual license owner of either the legacy Beat Making or Drum Mixing products, you can still use your plug-ins. However, accusonus will not be providing additional product development and support for these products.
Please use the relevant product keys you have received via email along with your purchase, to continue using the plug-ins. You can locate the installers here.
Sadly, an offline activation is no longer available. That is why we have raised the number of activations to 10.
You can consult this guide for the online activation.
Thanks a lot for your support along the way.’
There’s some links in the message, here’s the one for online activation:
https://support.accusonus.com/hc/en-us/articles/360016483160-How-to-activate-Music-Production-products-using-Online-Activation