Hi, I have used a command “!talk” on my stream for a while and it started to give a “no output” message when it was used a few months ago, but I have seen another channel using the same command and it is working fine for them.
This is the right way to make it work, however, the API it relies on is not free, its dev offer it for free to NightBot’s users, but they have to pay a monthly cost for it, so it’s possible it reached the end of the monthly requests amount it was paid for, or the dev decided not to support it anymore: it’s not listed on their website anymore.