The font size in the Biz App, including Kiosk Mode, can be adjusted to improve the display on your iOS device.
On your iOS device, open the Biz App and navigate to Kiosk Mode. Swipe down from the top-right corner of your device to access the "Text Size" option in the Control Center.
Adjust the text size and select the Mariana Tek App Only option. Then, close and reopen the app to see the updated font size.
If the "Text Size" option is not in your Control Center, go to Settings > Display & Brightness > Text Size. This will change the text size for all apps that support Dynamic Type.