Yhyjyk

I am having some issues installing PowerShell on my 32-bit Kali Linux PC. 
I followed this guide and started with:

apt update && apt -y install curl gnupg apt-transport-https

Next, I downloaded and added the public repository GPG key so APT will trust the packages and alert the user to any issues with package signatures.

curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add -

With the GPG key added, I added the Microsoft package repository to its own package list file under /etc/apt/sources.list.d/ and updated the list of available packages.

echo "deb [arch=amd64] https://packages.microsoft.com/repos/microsoft-debian-stretch-prod stretch main" 
 > /etc/apt/sources.list.d/powershell.list
apt update

No errors so far indicated in the update process, Microsoft sources are in my source.list, and everything should be good to go.

When I execute:

apt -y install powershell

I get:

root@kali:/opt# apt -y install powershell
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package powershell

You have successfully added the repository for Powershell to your sources.list.

However, you report to be using a 32-bit architecture system. Your output of apt-cache confirms that your Repositories do not contain the Powershell package.

Taking a look at the Powershell GitHub, it appears that Microsoft does not provide a Linux package for Powershell for 32-bit Linux systems. All of the source and binary packages available for Linux here are for 64-bit systems. If you are familiar with building from source, you could potentially build a 32-bit package, but that is a different kind of question and may not actually work if 64-bit Powershell has hard dependencies on specific 64-bit instructions.