A payload of jwt query_token should contain a customer's id and/or customer's reference field(s)

e.g.

{
"id": "63183fbae04e4d2ad89c30a0",
"reference": "067wgvm3ynmaxv04daqp"
}

These fields might be included in the payload which is obtained from the search stage (but only in case these fields were provided in query parameters)

e.g.:
GET search
{{url}}/v1/customers?id=63183fbae04e4d2ad89c30a0&reference=067wgvm3ynmaxv04daqp

This is your PowerBoard API Public Key