If you want to delete all your old Twitter DMs (which I think is a good idea even if Twitter might retain copies of them somewhere), and also your historical likes, RTs, and any tweets you don’t want to keep, I made a Twitter app for that.
It’s called Semiphemeral and it’s pretty easy to use. I posted instructions for how to do it https://twitter.com/semiphemeral/status/1591258781098594304?s=46&t=L4aWvmyNxEFRL6eULgeO-A
Semiphemeral on Twitter

“As you watch in horror/delight as Elon burns this site to the ground you might be pondering your privacy 🤔. Do you have YEARS of tweets, likes, and DMs? https://t.co/EF6AVCPm2O Gather 'round, friends, while I show you how to DELETE THEM ALL (or as much as Twitter's API allows)”

Twitter

@micahflee dude. This is amazing. Love it!

“In order to prevent fascists from using this free privacy service, Semiphemeral keeps track of Twitter accounts used by prominent racists, misogynists, antisemites, homophobes, neo-Nazis, and other fascists”