This plugin is built on browser API. No external API is used. Here is the API used speechSynthesis
That is why it doesn’t support all android phones aslo all languages. Here you can check which android phone and which device support this speechSynthesis API
Another issue speechSynthesis API is differ browser to browser also device to device . So it changes the voices and languages based on browser. one language may available on desktop
It can be not available on mobile phone. One voice may available on desktop, it may be not available on android.
If you still facing problems regarding browser issues please on a ticket.