Unable to find the comma in the Sinhala Keyboard layout on MacBook running macOS Sonoma

I will press the several keys in that row for you to get a clear idea. Of course, the comma must be in the same key having the fullstop which must be activated with Shift. That is the standard Wijesekara (unicode) layout.

ව/ළු න/ණ ක/ඛ ත/ථ ./* ්‍/‍්

As you can see, instead of the comma, there is asterisk. There are lots of redundant key mappings in this layout. I will also attach screenshots of the sinhala keyboard layouts.

This is the normal keyboard layout.

This is when I press Shift key.

This is when I press the Option key.

I can't find the comma. And just see how many unnecessary redundancies are there.

Yes, I bought this laptop from Japan. But I am using English. And I want to type both in English and Sinhala. Anyway, it must show the comma because it already shows all the other Sinhala letters. It is some fault from Apple.

Yeah, my keyboard is Japanese, but my locale is English. I am not running in Japanese.

I also thought of creating a substitution. So, when I press Shift+fullstop, the asterisk (in my mac) gets automatically substituted by a comma. The problem is, it substitutes even when I type in English.. haha... then I tried to substitute some other keys like ¥ to get it done, but the substitution does not occur. I don't know why.

As you suggested, I also thought of using an external keymapping app like that, but I don't like to use a serious app just to get something so simple done. It's unacceptable that Apple is so negligent.

Thank you Tom for your kind support. Really appreciate your efforts. :)

Thank you Tom. I downloaded it.

I pasted your file into the keyboard layout folder, and now it works perfectly. :) No need to install an app. Thank you very much. My problem was perfectly solved.