Does a Metal Roofing Need an Underlayment?

https://wiki-spirit.win/index.php/Ideal_Underlayment_for_Metal_Roofing_Review_in_2020

TRI-FLEX ® XT synthetic roof covering is an underlayment product used to supply a waterproofing area between the steel roofing and the ceiling below. The only way to supply extra water as well as wet proofing