Khmer Unicode

Dear sir /madam,

I am kimhong from Cambodia.

Now a day I am using accounting system “ Quickbook premier 2020”. This accounting is used english language is really smooth and normal.
By the way, when I was trying to type Unicode on this accounting system, it displayed ??? Character… but when type Chinese language or Arabic language it is showed smoothly…

Do I need to buy Khmer Unicode license or any solution ?

Please let give me some advice .

My email :

My telegram and what app: +85510303979

Thanks .