I started Flash Player installation with Chrome but it then reopened with my Default browser,which was Firefox 57. Later, I checked my Chrome, even though it‘a got Flash in Setting, I still can’t play music. I wonder whether or not I have my browser installed Flash Player and which is the target browser? Kinda Urgent...
Google embeds Flash Player in Chrome, so there is no need to install it manually, however, Google disables Flash by default and forces users to enable it. See Use or fix Flash audio & video - Computer - Google Chrome Help for assistance.
If you've worked through Google's support page and Flash is still not playing, and you are sure the content you are attempting to view/hear is Flash, it's possible the Site Engagement Index score is too low. See Site Engagement - The Chromium Projects and Google Groups
As for the default browser launching after installation, this is normal workflow. As long as you selected the correct installer file for the browser you want to view Flash content in (e.g. ActiveX Control for IE, NPAPI plugin for Firefox, PPAPI for Chromium-based browsers) it'll install for the correct browser.
Thank you very much for your reply.