All you have to do is on the very last line of your startup file (right after stat creation and before your actual game) is to include something like
*sm_init mygame | 3
It will not let your game run in cside but when uploaded to dashingdon it will work as long as you enable the pluggin in your settings. I recommend just commenting it out while you’re testing for bugs in CSIDE and then uncommenting when you’re ready to upload.
You can replace mygame with whatever you want and you can change the three to whatever number you want to increase the number of save slots.
I hope this helped 