I found a nice hack in Newsboat that allows me to send articles to my Todoist inbox instead of opening in the browser.
For that, you need to have a todoist-cli installed, and add the following to your newsboat config: macro y set browser "todoist-cli q %u &" ; open-in-browser; set browser "firefox '%u'". To activate macro, press , + y or whatever you bound for your macro activation.
This temporarily replaces Newsboat's browser with a command that sends the URL to the Todoist inbox, and I don't have to open it in the browser, and click "Add as a website" later (I use todoist to keep track of everything I want read, listen or watch).