DFR0604 PWM Help (External Power supply)

Hello everyone,
 

i have the following setup:
 

Raspberry Pi Zero with a DFR0604 IO-HAT (https://wiki.dfrobot.com/I_O_Expansion_HAT_for_Pi_zero_V1_0_SKU_DFR0604)
And i want to control a small pump like this one:
https://botland.de/pumps/14164-6v-wasserpumpe-5904422342401.html
which states: 6V and 2A as input.
So i would like to connect a 6V/2.5A external power supply to the +- of the PWM of the IO-Hat. However i cannot find information, what amperage the hat can use.
Ideally i would also like to secure the connection between hat and powersupply with a fuse.
 

So does anyone know if this setup will work or what kind of amperage the IO-hat can work with? 
Thanks in advance.