База данных Firebase Realtime Удалить все данные
curl -X DELETE "https://{{project_id}}.firebaseio.com/.json"
Sleepy Squirrel
curl -X DELETE "https://{{project_id}}.firebaseio.com/.json"// Can get databaseURL from firebase->Realtime Database which is the reference url
// Or from "databaseURL" key in your firebaseConfig
// By default it can looks like https://{projectId}.{server-location}.firebasedatabase.app
curl -X DELETE "{databaseURL}/.json"