How to add gap between chart and legend?

[czater]

Hello!
I want to add gap between charts and legend but...I don't know how :s I tried xOffset, yOffset but it does nothing for me :/
I ended with something like this:

How to set minimum offset or something like that? Thanks in advance :)

[liuxuan30]

does extraBottomOffset work for you?

[czater]

thanks you!