Split Keys in GarageBand

Over and over again people ask you how to split the midi controller keyboard connected with a midiinterface to Garageband. I would like to play one instrument with the left hand and another instrument with the right hand..I havent found any answer to this question in this community..How can I do it...

Does it mean it is not possible or it is only possible with logic pro that runs only with ox11 and higher and would need even a newer computer...

thanks for your answer