You used to be free for me but now is not.

I have used You ai for like 2 years often and always free.it would allow me to use the express option for chatting endlessly and I was able to have very very long conversations with it.
Recently I log on to find i have a 25 message limit even on express mode and there is no way to get more without paying. Has you ai just been put behind a paywall or was it always locked behind one and I somehow have been blessed enough to avoid it until now. can anyone explain it to me? I sure would love to be able to use the ai again