You can connect the Mini Card Reader and Pocket Card Terminal to your mobile device via the USB port instead of using a wireless Bluetooth connection. This gives you improved connection stability and speed and can also keep both your mobile device and Mini Card Reader/Pocket Card Terminal charged at the same time.
You will need any 2-in-1 USB host cable (also known as USB OTG) with a USB-C (for Pocket Card Terminal)/Micro-USB (for Mini Card Reader) connector on one end and a USB connector that is of the same type as the one used to charge your mobile device (e.g. USB-C or Micro USB). These are generic cables, sold by third-party manufacturers and are not made specifically for Viva Wallet. You can purchase them wherever USB data cables are sold at various technology accessory retailers.