creating and distributing private keys as pem files

I wanted to create and distribute some keys as filename.pem for people to ssh into a server like

ssh -i filename.pem username@machine.name

as is done for qwiklabs. With a bit of digging, found that the pem file is actually the private key and not the public key, and the whole process would be as follows.

ssh-keygen -t rsa -m PEM

cd .ssh

cp id_rsa filename.pem

cp id_rsa.pub authorized_keys

chmod 600 authorized_keys

References:

https://docs.oracle.com/en/cloud/paas/integration-cloud/ftp-adapter/generate-keys-pem-format.html

https://hnsws.blogspot.com/2006/01/adding-rsa-auth.html

https://serverfault.com/questions/706336/how-to-get-a-pem-file-from-ssh-key-pair

https://inkel.github.io/posts/pem-to-authorized-keys/

How to log on using the pem file with PuTTY on windows is via PuTTYgen as explained at 

https://aws.amazon.com/premiumsupport/knowledge-center/convert-pem-file-into-ppk/

for example.)