[Story]: Airgapped NGINX Plus installation on VM

Overview

As a user I want to deploy NGINX Plus on a fully air-gapped VM/host. No Internet access is possible. What I'm expecting is to run a script on an Internet-connected VM in order to build an "installation package" that I can copy on to the air-gapped VM/host, where the actual installation/deployment process will take place, without Internet connectivity.
This will help me quickly roll out NGINX Plus on my isolated infrastructure.

Which product or products does this request relate to?

NGINX Plus

Description

We currently don't provide documentation to assist users needing to install and run NGINX Plus on a fully airgapped virtual machine. What needs to be done at the moment is downloading NGINX Plus packages from MyF5 (applicable if and only if the end user is already a paying customer. If that's a prospect/we are at the presales stage, MyF5 is not accessible).
The need is to document a way to get something similar to what we have for NGINX Instance Manager (see https://docs.nginx.com/nginx-instance-manager/disconnected/offline-install-guide/):

• Run a script from an internet-connected host
• The script creates an "installation file" downloading all necessary content/packages
• The "installation file" is copied to the air-gapped virtual machine/host
• The installation process is started on the isolated virtual machine/host

Documentation should ideally support all Linux distributions supported by NGINX Plus. Having to prioritize them, I'd probably say RHEL, Ubuntu/Debian, Alpine might come first.

Acceptance criteria

As a user I want to be able to follow the documentation to deploy NGINX Plus pod on my fully isolated VM/host. All steps should be fully described and easy to perform.