Add a new config to an existing activation

curl --request POST \
  --url https://api.drip.re/api/v1/realms/{realmId}/web3/activations/{activationId}/configs \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{}'

{
  "id": "<string>",
  "activationType": "nft",
  "contractAddress": "<string>",
  "chain": "ethereum",
  "collectionKey": "<string>",
  "displayName": "<string>",
  "configs": "<array>",
  "createdAt": "2023-11-07T05:31:56Z",
  "updatedAt": "2023-11-07T05:31:56Z"
}