flash player alternative

If you're using video recording website from the potential employer, there's nothing you can do.  The potential employer needs to find new video recording software.

If you're using you're own video recording software, as OP mentioned there's other options avaialble.

For completeness:

Adobe announced Flash Player's end-of-life in July 2017 giving content creators, programmers, developers, IT experts, etc over 3 years remove Flash Player dependencies from their products. All modern browsers provide the capabilities necessary to do this in JavaScript.  This is an investment and prioritization choice, not a technical limitation. 

For reference:

• https://theblog.adobe.com/adobe-flash-update/
• https://www.adobe.com/products/flashplayer/end-of-life.html

Major browser vendors are deprecating Flash Player support.  Details specific to each vendor:

• Apple Safari - removed Flash Player support in Safari 14, released Sept 16, 2020
• Google Chrome - removed Flash Player support in Chrome 88, released Jan 19, 2021
• Firefox - removed Flash Player support in Firefox 85, released on Jan 26, 2021.
  • Firefox ESR 78 will support Flash Player for the time being, assuming the Flash Player NPAPI plugin is already installed as it’s no longer available for download.
• Microsoft Edge - removed Flash Player support in Edge 88, released Jan 15, 2021