get a command block and put the command [Fill ~ ~1 ~ ~ ~1 ~ minecraft:TNT]

next, set the command block to repeat and always active

then get a flame bow and shoot a arrow at the TNT. when the TNT explodes, it will cause the arrow to go flying, but then the arrow will teleport back to the next TNT that explodes. the arrow doesn't do any damage, but it is still an entity. you can also shoot a bunch of normal arrows at the TNT, then cause the TNT to explode with a flame arrow, or another method, and the normal arrows will also do the same thing

if it doesn't work at first, try again at a different angle

here is the youtube link

https://www.youtube.com/watch?v=ZKug_eekpLA