Um... Bro?

In Australia a girl might refer to him as a "mate" - meaning someone to whom the girl is close but not romantically involved with. She might say "we're just mates" to describe the relationship to her girlfriends. This is probably an Australian term not readily transferable to other English speaking countries. By the way I have never heard of the term "ladybro" at least not in any English speaking country but that may be because I am not familiar with teenage/young adult vocabulary.

Just, her best friend? Or, "guy friend", if you don't focus on how deep their friendship is. I guess for older women there's also the figure of the "walker" (temporary male escort of socially prominent women attending usually public events), which can intersect with 'confidant' ("Although this distinction has not always been observed by writers, confidante is generally used for a female confidant. The word confidant is more frequently used to describe a man, but it may be applied to either gender.").