curl --request PATCH \
  --url https://api.lava.so/v1/account/fallback \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "fallback_chain": [
    {
      "url": "api.openai.com/v1/chat/completions",
      "model": "gpt-4o-mini"
    }
  ]
}
'

{
  "success": true
}