You can get the original Botpress (called v12) which is open source here:
https://github.com/botpress/v12
There's community support available for it on the
#1112845893931110402 channel, however, please note that Botpress Cloud (which can only be provided as a managed service from Botpress, cannot be installed on-prem) is a much more full featured and modern product, as v12 doesn't come with the new generative AI features BP Cloud has.