set value of input text using javascript, but... -- 2

Yes, you read it right. I just need to set value of sn input field, but not just like [login to view URL] = 'xyz'; Code should be equivalent to keyboard typing so that all related event listeners like input, focus, keypress, blur etc are called as they get called when we type manually. Actually I need this to automate a website, but when I'm just setting the value and submitting the form, it logs me out. But some chrome extensions and apps are achieving this via js, but I don't know how. I've tried many things but everything failed. If you're a JS expert and think you can do this, DM and I'll give you website and other details.