Command doesn't work using target selectors

I've made a small mod which allows you to teleport to waypoints created with th Xaero's Minimap mod without cheats activated or without being OP. 

The mod works perfectly using, for example, the command /tpto @s 90 90 90 only either if you are OP or if you are in a singleplayer world.
If you are in a multiplayer with cheats enabled and you aren't OP tho, if you'll use a target selector the command won't work anymore: you have to type in your username instead.

Is there a way I can allow also non OP players to use target selectors?