if there is Enhancement in JIRA defect, what is best way to enter as new Product Backlog

[Nic Brough -Adaptavist-]

It's hard to say without knowing what your terms (Enhancement and defect) mean to you and how they should be handled by your process.

At a guess, I'd say you're using "defect" to mean "we found something in testing that needs a fix", but then "enhancement" means "while testing or fixing a defect, we had a good idea for a new thing".  In that case, I'd create a new issue for the the enhancement so it goes into the backlog for planning as normal, and link it back to the original defect to say where it came from.

But I am guessing there!