Found in https://packages.ubuntu.com/focal/i386/libasound2-dev/download

[Colin Watson]

On Fri, Mar 26, 2021 at 10:43:41PM -0400, Tyler Foster wrote:
> Package: libasound2-dev
> Status: install ok installed
> Priority: optional
> Section: libdevel
> Installed-Size: 660
> Maintainer: Ubuntu Developers <ubuntu-devel-discuss at lists.ubuntu.com>
> Architecture: i386
> Multi-Arch: same
> Source: alsa-lib
> Version: 1.2.2-2.1
> Provides: libasound-dev
> Depends: libasound2 (= 1.2.2-2.1)
> Suggests: libasound2-doc
> Description: shared library for ALSA applications -- development files
>  This package contains files required for developing software
>  that makes use of libasound2, the ALSA library.
> 
> 
> *Value should be 1.2.2-2.1ubuntu2.3 .*

1.2.2-2.1 was the version of that package in 20.04 at the time it
released; we don't update what shows up in the unadorned "focal" suite
after release.  1.2.2-2.1ubuntu2.3 was a post-release update, so that
would be in the "focal-updates" suite
(https://packages.ubuntu.com/focal-updates/i386/libasound2-dev/download)
instead.

packages.ubuntu.com is a very cumbersome way to actually fetch
individual packages rather than just searching and browsing around
though; you should instead use tools such as apt that will deal with
resolving dependencies and fetching the correct version of the package
for you.

-- 
Colin Watson (he/him)                              [cjwatson at ubuntu.com]