Why there is no simple yes or no
Roof tiles are made to shed rain, not take a concentrated jet of water at close range. Some modern tiles can cope with careful cleaning, while older or fragile ones can be damaged.
What can go wrong
Too much pressure can strip the surface, crack weak tiles or force water into gaps. There is also the obvious issue of working safely at height.
Check the roof first
The tile type, visible damage, pitch, access and amount of moss should all be checked before choosing a cleaning method. Pressure washing should never be the automatic choice.
Cleaning is not repair
A clean will not fix cracked tiles, failing mortar or a leak. Those problems need a roofer, and they should be dealt with before cleaning if necessary.
Not sure about your own property?
If you are in Ryedale or nearby, send Will a couple of photos and a short description. He can usually tell you whether the surface needs a closer look before quoting.