Can't create a username just after installing Ubuntu and can't switch to WSL 2

[Sandman192]

Version

Edition Windows 10 Pro Version 21H2 Installed on ‎7/‎6/‎2021 OS build 19044.1706 Experience Windows Feature Experience Pack 120.2212.4170.0

WSL Version

• WSL 2
• WSL 1

Kernel Version

5.10.16

Distro Version

Ubuntu 20.04

Other Software

No response

Repro Steps

wsl --install -d ubuntu

Expected Behavior

Ubuntu asks me to create a Username but give me this instead.

adduser: Please enter a username matching the regular expression configured
via the NAME_REGEX[_SYSTEM] configuration variable. Use the `--force-badname'
option to relax this check or reconfigure NAME_REGEX.

Actual Behavior

wsl --install -d ubuntu

Diagnostic Logs

No response

[Sandman192]

I found out you can't use capital letters in username.
Windows WSL site doesn't mention that.

[laurafstrube]

If anyone is still following this thread, is there a way to return to the automated "enter username" prompt?

I received this error and "CTRL-C'd" out of the prompt thinking I could come back and start over once I'd figured out what was going on.

[Gunhedo]

I found out you can't use capital letters in username. Windows WSL site doesn't mention that.

Thank you random user it solved the problem with your statement! :)