There is the possibility to import Literal from typing_extensions to allow this to work for 3.6 (since Typer still says it support it despite being EOL) and 3.7 as well. This may be a moot consideration soon though since 3.7 goes EOL in June 2023 as well if there are any plans to drop unsupported Python versions at some point.

This may require adding a specific dependency for typing_extensions, but it's currently being installed by another dep regardless from some of the CI runs I checked for 3.6+ 4.1-4.4 depending on the Python version.

Example implementation for using typing_extensions

Amazing, thank you @blackary! 🚀

And thank you everyone for the discussions and help. ☕

Thanks @svlandeg and @Kludex!

This will be (finally) available in Typer 0.19.0, released in the next few hours. 🎉