I can recommend this service for deleting all your tweets
Several weeks ago, I used Cyd, previously named "Semiphemeral," to delete all my tweets, and it worked. Recommend. It's an app that runs on your machine, you don't have to pay to get rid of the tweets, and I didn't get rate limited or anything while using it. I used this one because it was soft-recommended by Wirecutter.
I highly recommend deleting all your tweets. There is no reason to allow this service access to your text and no reason to allow it to act as a representation of yourself online. The guy who owns it has nobody's best interests at heart but his own, and he is going to continue to twist that tool and all the data on it into an expression of his own power and loathsome politics. Delete your data.
Increasingly, I choose to have only one representation of myself online, which is this website. I have complete and total control over which blog posts appear on this site and I'm glad to exercise that control in the precise way that makes me most comfortable and confident. I can't recommend this level of fine personal control over your self enough!