What do I say about why I left my last job? - what worked for you?

I have an interview next week and I am unsure how to explain why I left my last job as a software tester. I would rather hear the honest version than the polite one. I do not want to blame the company. Do they ask follow-ups?

Say it plainly and move on to what you can do. Interviewers usually move on if you do.

Practise it out loud with a friend. Mine felt natural after the third try.