Dynamic buttons using Custom action

Hi,

I am tring to create severals buttons dynamicly using custom action.
Here is JSON that I tried :
But I can't find the proper JSON for Buttons
{
"type": "choice",
"payload": {
"buttons": [
{
"name": "Label A",
"request": {
"type": "path-9x2sh3elw",
"payload": {
"label": "Label A",
"actions": []
}
}
},
{
"name": "Label B",
"request": {
"type": "path-dm3533een",
"payload": {
"label": "Label B",
"actions": []
}
}
}
]
}
}

No buttons are being rendered.