When connecting to an Amazon EC2 Linux instance, Amazon does not use passwords. Instead, they require public/private key exchanges. When you create an EC2 Linux instance, you have the opportunity to download and save the private key (.pem) file, which can be used to generate the private key.
If you have the .pem file and want to connect using Chrome Secure Shell on Windows, perform the following steps:
Rename your .pem file to the same name without the .pem extension (e.g. from mykey.pem to mykey)
Create a new blank file with the same name as your .pem file and a .pub extension (e.g. mykey.pub)
Using Secure Shell, import the two files from steps 1 & 2
As of this writing, I don’t know the exact mechanics of why this works. I can verify this works on both Windows as well as ChromeOS. For ChromeOS, you can simply place the two files in a location in your Google Drive and import them from Google Drive.