curl --request GET \
  --url https://api-m.paypal.com/v1/commerce/billing/customers \
  --header 'Authorization: Bearer <token>'

{
  "customers": [
    {
      "id": "f772b19c-c5c2-426d-8871-346a6cd094c5",
      "name": "TechStart Solutions",
      "external_id": "5eb02857-a71e-4ea2-bcf9-1753826282",
      "email": "finance@techstart.io",
      "address": {
        "line1": "123 Innovation Way",
        "line2": "Suite 400",
        "city": "San Francisco",
        "state": "CA",
        "postal_code": "94087",
        "country": "US"
      },
      "phone": "+1 (555) 789-1234",
      "payment_method_token": "6ta69628uw121251c",
      "payment_method_type": "CARD",
      "metadata": [
        {
          "key": "Purchase Order",
          "value": "PO-2023-4521",
          "display_in_invoice": true
        },
        {
          "key": "Sales Region",
          "value": "West Coast",
          "display_in_invoice": false
        }
      ]
    },
    {
      "id": "3c25d14a-5fe4-455e-8862-dfb07d384d08",
      "name": "TechStart Solutions",
      "external_id": "5eb02857-a71e-4ea2-bcf9-1753642317",
      "email": "finance@techstart.io",
      "address": {
        "line1": "123 Innovation Way",
        "line2": "Suite 400",
        "city": "San Francisco",
        "state": "CA",
        "postal_code": "94087",
        "country": "US"
      },
      "phone": "+1 (555) 789-1234",
      "payment_method_token": "6ta69628uw121251c",
      "payment_method_type": "CARD"
    }
  ]
}