Be sure to check out the NaNo Sponsors' area for free and discounted stuff as well as free trials.

https://nanowrimo.org/offers

I tried Dabble previously when writing my novel in 2019. I liked it and it's still available for me to view. I need to pay to be able to work on it, though.

This year I'm testing out Scrivener. I hear there's a learning curve with it, but they are offering a Zoom tutorial/info session, so that's cool.

Next time I'll probably try 4TheWords. I think this would be especially awesome if you are writing in the fantasy genre since that's what it seems to be using in the gamification process. Of course, anyone can use it to write anything, but I think my own brain might get confused if I'm slaying monsters with my word count while writing about an alpaca farm. I've heard good things about it, though!