To enable the Flash Player plugin by default in Chrome, and run Flash content automatically when you encounter it, please follow the steps below:
  • Click the Customize and control Google Chrome    button at the top right.
  • Click Settings.
         
  • Scroll down to the bottom of the Settings page, and click the Show advanced settings… link.
         
  • When the page expands to display advanced settings, scroll down to the Privacy section, and click the Content settings… button.
         
  • In the Content settings window, scroll down to the Plugins section. The new default setting for Chrome is Detect and run important plugin content. If you want to play Flash content in Chrome by default instead of having it blocked, select Run all plugin content. If you want to enable click-to-play plugins so you can choose to run Flash when you encounter Flash content, select Let me choose when to run plugin content instead. Once you have made your selection, click the Done button to save your edit.
         

Source: https://techhelpkb.com/how-to-unblock-flash-in-chrome/