It was a a yellow sticker stuck on the windscreen with a piece of paper inside with the charge of £60. It was a private road for residents. I havent got the picture of the sign yet

Hi im wondering if anyone can help me, i got a parking charge notice from these people asking to pay. after doing some researches im hestitating to pay because of what i read from others drivers who got charged. What do i do? They clearly did have their bright red signs up in the area that i parked it just seems so odd that they are asking to pay by paypal and not automated payment line over the phone. Please help me what should i do