Error while using promise

addnewmessage(msg) {
    if (this.buddy) {
      var promise = new Promise((resolve, reject) => {
        this.fireprivatechats.child(firebase.auth().currentUser.uid).child(this.buddy.uid).push({
          sentby: firebase.auth().currentUser.uid,
          message: msg,
          timestamp: firebase.database.ServerValue.TIMESTAMP
        }).then(() => {
          this.fireprivatechats.child(this.buddy.uid).child(firebase.auth().currentUser.uid).push({
            sentby: firebase.auth().currentUser.uid,
            message: msg,
            timestamp: firebase.database.ServerValue.TIMESTAMP
          }).then(() => {
            resolve(true);
          }).catch((err) => {
            reject(err);
          })
        })
      })
      return promise;
    }
  }

At the then() before resolve(true) it shows " unresolved function or method then()

When i try executing the code it gives an error like this
"
Typescript Error
Property ‘catch’ does not exist on type ‘PromiseLike’.

"

I am new to the web programming and stuff… so can anybody please tell me what i am doing wrong here

Solved:sweat_smile::sweat_smile::sweat_smile::sweat_smile::sweat_smile::sweat_smile::sweat_smile::sweat_smile::sweat_smile::sweat_smile: