Command for filling storage with items..? [closed]
Yes, you can specify the content for every slot like this:
data modify block <coordinates> {Items:[{Slot:0,id:"stone",Count:64},{Slot:1,id:"stone",Count:64}]}
But if there's space above and you have time, you can just put a hopper on it and put summon Item <coordinates> {Item:{id:"stone",Count:64}} into a repeating command block. That has the advantage that it works the same for every inventory type (even chest minecarts) and it can flow through sorting systems or other complex setups normally.