@ionic-native/printer pick method returns null

When I calll the pick method, the printer selection window does not appear and the method returns null.

  displayPicker() {
    this.printer.pick().then(pickSuccess => {
      console.log('Printer picked: ', pickSuccess);
    }, pickError => {
      console.log('Pick printer error: ', pickError);
    });
  }

The console logs : Printer picked: null

Ionic:

Ionic CLI : 6.12.1 (/usr/lib/node_modules/@ionic/cli)
Ionic Framework : @ionic/angular 5.3.4
@angular-devkit/build-angular : 0.1000.8
@angular-devkit/schematics : 10.0.8
@angular/cli : 10.0.8
@ionic/angular-toolkit : 2.3.3

Capacitor:

Capacitor CLI : 2.4.2
@capacitor/core : 2.4.2

Utility:

cordova-res : not installed
native-run (update available: 1.2.2) : 1.0.0

System:

NodeJS : v12.19.0 (/usr/bin/node)
npm : 6.14.8
OS : Linux 5.4

I have also filed an issue with cordova-plugin-printer:

Any help appreciated, thanks.