Web portal > account/profile > account settings > billing Then there's an orange "add/edit subscription" link and a "cancel subscription" link. The process is

Web portal > account/profile > account settings > billing Then there's an orange "add/edit subscription" link and a "cancel subscription" link. The process is well documented in an article on their help centre. A simple DuckDuckGo search brings up the help centre article as one of the first results.