curl --request POST \
  --url https://api.mixpeek.com/v1/organizations/credits \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "credits": 123
}'

{
  "previous_balance": 123,
  "credits_added": 123,
  "new_balance": 123,
  "tier_upgraded": true
}