Assuming that this is your manual, there is in fact no USB port at the board. But there should be a RS-232 Port (labeled X18 in the manual at page 16). Maybe you can use that one? At my THZ 304 eco the RS-232 port seems to be gone for a USB-B port.
I can provide some pictures for the THZ 304 if someone is interested, but pictures of the port is quite impossible to do as the port is directed to the backplane of the casing.
In either way, a look in the docs of your heatpump concerning internal ports is worth it