curl --request POST \
  --url https://api.interchange.io/api/v2/buyer/discovery/{discoveryId}/apply-proposal \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "proposalId": "proposal_abc123"
}
'

{
  "discoveryId": "<string>",
  "proposal": {
    "proposalId": "<string>",
    "name": "<string>",
    "salesAgentName": "<string>"
  },
  "totalBudgetUsed": 123,
  "productsApplied": 0,
  "productsSkipped": [
    "<string>"
  ],
  "products": [
    {
      "productId": "<string>",
      "salesAgentId": "<string>",
      "selectedAt": "<string>",
      "groupId": "<string>",
      "groupName": "<string>",
      "bidPrice": 123,
      "budget": 123
    }
  ],
  "totalProducts": 0,
  "budgetContext": {
    "sessionBudget": 123,
    "allocatedBudget": 123,
    "remainingBudget": 123,
    "budgetWarning": "<string>"
  },
  "campaignBound": true,
  "campaignWarning": "<string>"
}