Abdulla Hi, it is indeed not possibile through Tabacchi.
You’ll have to deposit using Barzhalen affiliated store (Penny market, PAM etc…)
Ti do so simply click the “add money” on your app and choose the amount you would like to add.
Remember that only 100€ a month are exempt to fees. You’ll receive a barcode that will be scanned by the store and you’ll give them the money.