I am building a dashboard so I can easily view how many people currently have a specific label in my facebook messenger. I'm just developing this for my page that I'm admin at, so it's only for this one page.

The final result is this:

Label 1  - 38 People
Label 2 - 82 People
Label 3 - 47 People

First I get the participants using this endpoints: {page-id}/conversations?fields=participants I get this sample:

{
"data": [
{
"participants": {
"data": [
{
"name": "Particiapnt's name",
"id": "<psid>"
},
{
"name": "My Page Name",
"id": "<my-pageid>"
}
]
},
"id": "<thread-id>"
}
]
}

Now when I use participants id (psid) to get custom labels using this endpint: /custom_labels I get this error:

{
"error": {
"message": "Unsupported get request. Object with ID 'xxxxx' does not exist, cannot be loaded due to missing permissions, or does not support this operation. Please read the Graph API documentation at https://developers.facebook.com/docs/graph-api",
"type": "GraphMethodException",
"code": 100,
"error_subcode": 33,
"fbtrace_id": "A5kFh5U-xSMB83ZnQrbzEfy"
}
}

Please help.