"error: Puppet not found" on fresh install

goal and setup process

My goal is to bridge private Discord messages to my selfhosted Matrix instance. I've followed the installation instructions and even tried to clone from gitlab instead of github, as recommended in another issue. The installation yarn install and yarn build works out of the box, yarn start -- -r didn't work but that was also documented in another issue (those issues really help alot for a beginner like me). I successfully generated the registration file and added it to my homeserver.yaml, which seems to work so far. yarn start runs without any errors and the initial setup of the database file seems to work too.

issue

My issue is with linking the Discord bot account. I generated my token but when I message the bot directly @_discordpuppet_bot:matrix.myserver.com and send the link bot tokeninsertedhere I get the response "ERROR: You don't have permission to use this bridge". The log tells me "[MatrixEventHandler] error: Puppet not found. Something is REALLY wrong!!!!" which I find unintuitive and I honestly don't know the next step. I've worked myself through the log file in "silly" mode but it's not clear to me what is missing. I've also purged everything and went throught the installation process three times in total, no luck - same error. Can someone please give me a hint? What additional information is needed to get a clear picture on this error?