How do i make a block regenerate when I break it?

[Merrical]

the command i'm using:
on break of coal ore:
set block at the break of coal ore to coal ore
send "&9Yay" to player

Isn't working anyone know why?
[doublepost=1595889091,1595888969][/doublepost]the
"send "&9Yay" to player" is just so i know it works. it does

 

[neo]

Try

on break of coal block:
    set event-block to coal block
    send "&9Yay" to player

If this is not working, try

on break of coal block:
    set the block at event-block's location to coal block
    send "&9Yay" to player

 

[Merrical]

here
[doublepost=1595974495,1595974449][/doublepost]on break of coal ore:
send "&8'Breaking Coal Ore'" to player
wait 1 tick
set block at location of event-block to coal ore
[doublepost=1595974529][/doublepost]you could also replace the "send" to "do nothing"