Font based on Unicode range in font.conf

Question

I am trying to use one particular font, Noto Sans, for the Indic Unicode codepoint ranges starting at 0x0900 with the lines below added to /etc/fonts/conf.d/50-user.conf

My code is based on this answer on another thread

 <match target="font">
  <test name="family" compare="contains">
   <string>Noto Sans</string>
  </test>
  <edit name="charset" mode="assign">
   <name>charset</name>
   <charset><range>
    <int>0x0900</int>
    <int>0x09FF</int>
   </range></charset>
  </edit>
 </match>

However, this doesn't seem to work. I am running Xorg (Kubuntu 22.04).

Any help with the fonts.conf would be much appreciated!