How to summon tnt to a specific player’s location

Question

I was thinking of trolling my friend in our survival world. Essentially, I’d like to be able to press a button on a command block that will summon tnt or spawn a mob at his location. I know how to spawn a mob or tnt, but I don’t know how to locate him. I’d tell you what I’ve tried, but to be perfectly honest I have no idea where to start. If anyone knows the command it would be greatly appreciated! (I play on Bedrock 1.16 in case that matters.)

Answer 1

Put this in your command block:

execute <player> ~ ~ ~ summon <entity>

Whatever the player's name is, put that on <player>, and summon any <entity> given in the command.

You can try something else, however. Changing the coordinates where the player is standing by y + 75 will make it look like they nearly got nuked.

Simply:

execute <player> ~ ~75 ~ summon tnt

Answer 2

The accepted answer works for 1.16, the updated syntax for 1.20+ version is:

/execute at <player> run summon tnt ~ ~ ~