I've heard people using this slang betcha.
What is the difference between you betcha and I betcha?
'You betcha' is someone insisting something, such as 'You betcha' in return to someone asking if another can perform a certain task.
ex: "Can you mow my lawn while I'm away?"
whereas 'I betcha' is typically someone using the term as it was originally intended, ie, betting.
ex: "I betcha can't beat me in soccer!"
Does this help?
I betcha is colloquial for I bet you and You betcha is colloquial for You bet. In AmE.
I bet you and You bet.
Often, "you bet" is seen like this: You bet I can.
And the meaning, as an answer, means: Of course, I can.
'You betcha' can be understood as a colloquial short form of 'you can bet on that', meaning it would be a safe bet to say yes. It's used as an affirmative answer to a question. 'Does that work?', 'Yes, you betcha!'
I think @Valentine has recognized correctly what 'I betcha' might mean.
I don’t disagree with anyone else’s definition of “you betcha”, but I agree with everyone who seems confused by “I betcha”- I have never heard this before. I am not from Minnesota but in the U.S. “You betcha” sounds like something a Minnesotan would say, and this glossary of Minnesota terms confirms it: https://www.brownielocks.com/minnesotatalk.html
YOU BETCHA: A confident affirmation. Example: "Are you going to the hockey game dis weekend?" Answser: "You betcha I sure am."