There is absolutely no way to get this answer based off of what we've learned.
You guys need to expand your aperture of correct answers.
"Call me if there is anything / call me for anything" should work.
It's silly to have to memorize precisely these two phrases not to lose a hart :(
This may seem unnecessarily hard and weird, but it is actually a fairly common expression, probably worth learning.
I'm realizing in spoken BP that it is rather common to leave various words out or shorten them when speaking. That will take some time to get used to.
'If there is anything call me, okay?' should also be right.