Hi @Lusine Avagyan
Thanks for reaching out.
If you're using Chrome, it's not possible to install local fonts on a tablet, because the font installer for the web app is only supported on macOS and Windows computers (this article). For context, when fonts are installed on your device, they're automatically added to the Figma file when you use the desktop app—or when you've installed Font Helper for the web app.
This article also mentions that support on mobile devices is limited: https://help.figma.com/hc/en-us/articles/360039827194-What-are-the-system-requirements-for-Figma#mobile
We'll definitely share your feedback with our team for future improvements, so please let me know if you have any other questions!
Thanks for your understanding.
Toku