Is there client for macbook?

Never was. And since the original game cannot run now on all the latest mac's (namely starting even from catalina as it dropped support for 32 bit apps), you couldn't have it on both intel and arm powered mac. The only way to think about any working game/client is to make it somehow as ios samp (which is even harder if you wanted to distribute it in app store as well) and launch its .ipa on your arm macbook. Anyway it will be still a mobile game developed for iphone/ipad. So, speaking about original GTA: SA for mac, you cannot even run a game on any current mac higher than Mojave (which is very old version for now), not to speak it has no sense to develop a client for that game version.