How do you install flash player behind a proxy?

Hi.

I'm trying to install flash player for firefox using the link here Adobe Flash Player Install for all versions

This is the 'web' installer that connects to the internet and then downloads the installer. But it won't work on our proxy.

We have a proxy that we have to use and the installer gives out the 'application initialization error' and the log under C:\Users\myuser\AppData\Local\Temp\Adobe_ADMLogs

After much testing it gives:

12/27/18 16:22:48:524 | [WARN] |  | ADM |  | ApplicationContext | HTTPSend |  | 22216 | Certificate not matching.

12/27/18 16:22:48:524 | [FATAL] |  | ADM |  | WorkflowManager | HTTPConnectorError |  | 22216 | Error occurred while getting application xml: -4 extended error: 0

[note, the xml fetch error is new. the cert issues has been a constant]

I have attempted to configure the proxy to allow all the URLs that I've managed to find using applications like wireshark, but none seem to be being blocked in the first place when I log into the proxy software.

Is there a full list of urls that I need to whitelist, the adm log does mention some, but not sure if full list.

I know I can get the full installers and that will work, but would like to get it working using the web installer.

Thanks.