Lithuanian letters on iPhone keyboard

Hey

My iPhone XS works just great.

Thanks for the recent new iOS update.

The only thing that I really miss on my phone, especially as a not native English speaker, is some (not all) Lithuanian letters. When I'm texting, writing posts on social media, using my Facebook Messenger app or just browsing the web on Safari, I don't get these letters to appear on my iPhone keyboard.

The two missing letters are: ą, ų. The rest works just fine.

How can this issue be solved?

Again, thanks.

Regards MJ