curl --request GET \
  --url https://api.togai.com/accounts/{account_id}/purchase_proposals \
  --header 'Authorization: Bearer <token>'

{
  "data": [
    {
      "id": "purchase.1zYnCiM9Bpg.lv25y",
      "pricePlanId": "pp.20dINmd0lBg.05sKa",
      "pricePlanName": "Advanced Tier",
      "type": "ASSOCIATION",
      "status": "PROPOSAL_ACTIVE",
      "paymentMode": "PREPAID",
      "pricePlanVersion": 2,
      "createdAt": "2020-01-01T00:00:00Z",
      "updatedAt": "2020-01-01T00:00:00Z"
    }
  ]
}