If you just want a “prettier font,” the installation steps (especially rooting or using ADB) are overkill. Stick to Samsung’s built-in “Choco cooky” or “Cool Jazz” – or use Google’s Noto Serif.
This is trickier because social apps use system fonts. However, you can use (like Fonts Keyboard ) that output text in Thonburi-style Unicode, but note: the recipient will only see Thonburi if they also have it installed. Otherwise, it falls back to default. thonburi font android