The HOTTAP requires a minimum of 10PSI and 6LPM to operate across the full flow range.
You’ll find that a lot of pressure pumps will have a pressure setting of at least 40PSI. So, the important thing to focus on is the flow rate.
If you use a lower flow pump (e.g. 4.3LPM) you will be able to use the HOTTAP on the minimum flow setting, but, the unit will cut out as you increase the water dial toward maximum. This is due to the unit requiring more water than what is being supplied.