Which is correct Maybe or May be

Question

Is May be correct English? or does one need to join the words like Maybe?

In one of the online grammar checkers, I entered this sentence: May be tell him about this problem

It showed a red mark on May be and auto-corrected it to Maybe.

Answer 1

Maybe meaning perhaps is written as one word.

They are written as separate words in a sentence like I may be late tomorrow if my car won't start.