curl --request POST \
  --url https://api.sequence.app/rpc/Builder/RemoveAudienceContacts \
  --header 'Content-Type: application/json' \
  --header 'X-Access-Key: <api-key>' \
  --data '
{
  "projectId": 123,
  "audienceId": 123,
  "contactIds": [
    123
  ]
}
'

{
  "ok": true
}