My I-phone doesn't speak Nepali

Hello! I am madhusudan I am the new user of I-phone, recently I had bought I-phone 8 I am shifted to I-phone from an android phone. I like the I-phone due to its best accessibility feature for the blind.
Now let me proceed to my small problem, Actually when I was using Android phone their was no any problem in terms of Nepali text to speech. My native language is Nepali and for using with screen reading app I use to make Nepali text to speech as secondary language, there are some tts which reads Nepali like Google text to speech, there is nepali language included in google tts. There is also free and open source synthesizer in Android as well as in windows operating system named E-speak But now In my I-phone I am facing few problems while using voiceover specially with nepali text. When ever nepali
Language is detected voiceover use hindi voice for reading Nepali. In fact, most of the nepali people are using hindi voice for reading Nepali language, I have to say honestly, the hindi voice doesn’t read nicely, it’s sounds so crappy while reading and inaccurate too. I’ve must say hindi language is different from Nepali. ?
So is their any possibility of adding Nepali voice in voiceover?
Please Help me, if IOS could add nepali then it would be more better to use voiceover.
Thanks