how to deploy react native app access via qr code code example

Example: react native qrcode scanner permission

_requestPermission = permission => {var optionsif (permission == 'location') {      options = this.state.isAlways ? 'always' : 'whenInUse'}Permissions.request(permission, options)      .then(res => { this.setState({ status: { ...this.state.status, [permission]: res },        })        if (res != 'authorized') {          var buttons = [{ text: 'Cancel', style: 'cancel' }]          if (this.state.canOpenSettings)            buttons.push({text: 'Open Settings', onPress: this._openSettings,            })Alert.alert( 'Whoops!','There was a problem getting your permission. Please enable it from settings.',buttons,)        }      })      .catch(e => console.warn(e))  }