getting position of blocks using random block from tag

alright so i want to have a tool that creates blocks under yourself, but now i want a button that can delete all those blocks. the blocks are a custom block, and i want to get the X, Y, Z position of all blocks.

i thought looping through [Random block from tag] until its air and trying to get the position of that block so that i can delete it

how do i get the position of blocks???