There are two ways to connect your iPad to your USB Typewriter.
Method 1: Simply connect a USB cable to your iPad, using Apple's proprietary USB adapter, which they call the "USB Camera Adapter". Apple calls these adapters "Camera Connectors". If you have an iPad 1, 2, or 3, you will need the Apple 30-pin Camera Connection Kit, Otherwise, iPad 4, 5, and iPad Mini users will need Apple Lightning Camera Kit. If you have an Android tablet instead, you will most likely need a "USB-OTG" Adapter -- but first make sure that your tablet supports USB-OTG connections.
Method 2: Put your USB Typewriter into Bluetooth mode, and then allow it to connect to your iPad over Bluetooth. First, power your typewriter by plugging it into any USB phone charger, power bank, or computer USB port. You can even use your iPad to supply power. While plugging it in, hold down the "B" key to enter Bluetooth mode. At this point a red light will indicate that the USB Typewriter is searching for a Bluetooth connection. The USB Typewriter must then be added to the iPad's list of paired Bluetooth devices by going to Settings>>General>>Bluetooth. Once connected, the USB Typewriter's red LED will turn green.
To mount your iPad on your typewriter to create an iPad stand, you will need to follow the instructions shown here.