I'll square ye up
I'll pay you back; I'll settle up with you later.
Get me a pint dere and I'll square ye up on Friday.

Shall I translate it into posh English for you, mucker?
Well hello, you've caught me mid biscuit. Here it is in posh English.
Do purchase me a pint and I shall reimburse you on Friday.
Questions
What does I'll square ye up mean in Ireland?
I'll pay you back; I'll settle up with you later.
How do you use I'll square ye up in a sentence?
“Get me a pint dere and I'll square ye up on Friday.”
Updated
On the list: Irish slang phrases