Directory doesnt exist CreateDir whit File

Ionic Framework ionic-v3
1

Who is my error??? help me


this.dirName = "folerConfig";

this.file.checkDir(this.file.applicationDirectory, this.dirName)
      .then(_ => {
        console.log('Directory exists');

        this.file.createDir(this.file.applicationDirectory, this.dirName, false)
        .then(
          (files) => {
            // do something
            console.log("success created dir");
          }
        ).catch(
          (err) => {
            // do something
            console.log("error created dir"); // i am invoking only this part
          }
        );

      })
      .catch(err => { 
        console.log('Directory doesnt exist');        
       });
2

Your problem lies in the phrase that comes immediately after cordova.file.applicationDirectory in the documentation: “read-only”.