well sdcards are the cheapest and simplest.

But if you want to automate things, then raspberry pi's and the 'octo' family of sofyware is probably your cheapest bet.

I suppose it's not worth telling you to not go the creality route ?

anyway - this looks promising:
https://www.astroprint.com/3d-printer-farm-software

then there's this: https://www.3dprinteros.com/3d-print...ps-operations/

Also worth a read :-)
https://help.prusa3d.com/en/article/...l-mini_133279/

That lot should get you going :-)