Unable to locate emscripten

I know, it's plenty of similar questions, yet…

I want to try emscripten, just out of curiosity, to see if it makes C++ a viable alternative/complement to JavaScript/TypeScript in a webapp.

Trying to install it, this is the result:

   sudo apt-get install emscripten
   Reading package lists... Done
   Building dependency tree       
   Reading state information... Done
   E: Unable to locate package emscripten

Fine, I searched for this problem and I found this nice post
"Unable to locate package" while trying to install packages with APT

So I followed the steps and searched in packages.ubuntu.com for the emscripten package and found it in universe.

All good, so I open Software&Updates and I find that I already have universe enabled.

Of course, I've used both sudo apt-get update and apt-cache search. The last one gives me, indeed, this result

apt-cache search emscripten
emscripten-doc - LLVM-to-JavaScript Compiler

So it sees the emscripten-doc package, but not the emscripten package.

I have tried to do even sudo apt-get dist-upgrade as last resort and as suggested in another reply to another similar question, and then repeated the update and the search, but even this didn't fix my problem.

What am I missing?
Thanks.

Edit: adding some required infos.
My release is 20.04

lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 20.04.2 LTS
Release:    20.04
Codename:   focal

And the output of my update.

sudo apt-get update
Hit:1 http://it.archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://archive.canonical.com/ubuntu focal InRelease                      
Hit:3 http://ppa.launchpad.net/makehuman-official/makehuman-community/ubuntu focal InRelease
Hit:4 http://it.archive.ubuntu.com/ubuntu focal-updates InRelease              
Hit:5 http://it.archive.ubuntu.com/ubuntu focal-backports InRelease        
Hit:6 http://security.ubuntu.com/ubuntu focal-security InRelease
Reading package lists... Done