I placed UthmanTN1Ver10.otf into Special subfolder and added #AppFont : UthmanTN1Ver10.otf
In Application_Start I did Log (Font.CreateNew2 ("KFGQPC Uthman Taha Naskh", 20dip)).
Result: <B4IFontWrapper: <UICTFont: 0x7fd768641970> font-family: "KFGQPC Uthman Taha Naskh"; font-weight: normal; font-style: normal; font-size: 20.00pt>. Means IOS sees a font family.
HTML ... It's hard to test, because I don't know how a font looks. Guess, inside <style type=text/css> it's neccessary to do something like body { font-family: KFGQPC Uthman Taha Naskh; font-size: 20pt }