Khmer (km-yannis) keyboard does not work properly

Hi, I am on Fedora 38 and trying to type in Khmer language (km-yannis). However, it does not work properly. In short, I am not able to type any vowel, the combination of consonants and vowels, or any construction of a word at all.

Could anyone give a general idea of how it works on fedora? I am happy to try any workaround or contribute to fixing the issue.