On my adobe account page I go to my purchased products and subscriptions where I can manage the subscription for Extension Builder. There is a link for canceling the subscription. This link leads to the support page where I found a manual for canceling the subscription. This manual tells that I have to get in touch with the adobe support, but there is no way to get in touch with the adobe support. Instead I will be forwarded to some forums. That is why I am asking here.
Does anybody have a hint for me how to proceed?
I successfully canceled the subscription now.
Under the link
there are different possible contact options depending on the selected issue. Instead choosing the issue "Membership, account, payment" where I expected the option to cancel the subscription, I selected the issue "Adobe ID and signing in". After a click on the Still Need Help button there was a chat available, where I could let canceling the subscription.