How to Install a module on Drupal 8 in a docker environment when D8 asks for FTP credentials. (Devilbox)

To solve my problem I bypassed finding the FTP credentials.

I will change the accepted answer to the first correct answer that is not mine and a bypass.

First step, stopped using cygwin. Started using Powershell. Next step, navigate to the site's installation within devilbox:

/devilbox/data/wwww/<yoursite>/htdocs

Then run command:

composer self-update

Followed by:composer require drupal/<drupal module to add>

Magically, module is under the modules page on drupal 8.

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