I'm trying to remember the YA book I read about cancel culture and apologies

I read this book ages ago and I want to come back to it now that I am a writer exploring cancel culture and the volatile world of social media in my own stories. Here's what I remember:

• Genre is YA
• The main character is a girl called Winter who starts the story by making a racist tweet about a black kid winning a spelling bee. It gets a lot of traction and one of her friends, a black boy named Jason, cuts ties with her.
• Part of the backlash she receives is that her university of choice rejects her application, which upsets her greatly.
• She goes to a retreat for other people that have been cancelled and helps them write their apologies to the people that they hurt.

I'm sorry if this isn't enough details, my memories are foggy from the time that has passed.