Im trying set up shop so player can buy permision

This works fine if i want player keep buy that permision for me all the time 

"InstaRecycle": {
"description": "Allows to recycle Instanty",
"iconName": null,
"commands": [
"o.grant user TheSubWolf recyclerspeed.use"
],
"displayName": "InstaRecycle",
"cost": 25,
"cooldown": 0
},

My problem is in this line 

"commands": [
"o.grant user "name of who ever buys it" recyclerspeed.use"
],

is there way for playerID to be picked from user

From the plugin's page at https://umod.org/plugins/server-rewards#adding-a-command

$player.name is what you'd want.