swr meter connect

I'm trying to tune an antenna to work at 13.56 MHz. We've got a SWR meter at school with only one input. However, the antenna manual I've been reading says that I need to tune the antenna using a SWR meter with 2 inputs - one for the antenna and the other for the transmitter (in my case, an RFID reader). Does that mean that using the SWR meter at school is a non-starter?

The meter you use at school may have an internal oscillator. You can test it with a 50 ohm resistor and then an open and then a short circuit. You should get 1 for the first and infinity for the second two terminations.

I think somewhere is a misunderstanding.
Probably the SWR-meter with one input what you said, is actually a basic RF power meter with internal load.
You need a standard antenna SWR-meter, with one input (for transmitter) and one output (where you connect the antenna).