curl --request PUT \
  --url https://tilt.io/api/v1/backchannel/preferences/topics \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "topics": [
    "<string>"
  ],
  "threshold_exposure_pct_for_alert": "<string>"
}
'

{
  "id": 123,
  "user_id": 123,
  "topics": [
    "<string>"
  ],
  "threshold_exposure_pct_for_alert": "<string>"
}