Short can be good - "Forgive the typos" - "Excuse my typos" - "Sorry for the typos" Also, it's common to fix a typo with a * Typo: It's late, I hate to go to bed now Fix: *I have to go

All you have to say is, "I'm sorry for all of the typos in my last message! I'm sure it didn't make sense." Your apology can be very simple because typos are common and no one is very bothered by them, especially when they know they are chatting with a language learner.