You won't be able to. USB requires a host and a slave. The USB chip on the Axon only allows for slave, and you probably won't be able to find an adapter with host capabilities (it'll say if it does).
That said, we might be able to create a software UART to do what you want, effectively giving you 5 UARTs.
What devices are currently using the other UART ports of your Axon?
In WebbotLib Project Designer, you can easily create a software UART for the Axon. The disadvantage with software UARTs is that they are very slow, so you should use the device that transfers the least information on it.