Next you will see an entry at the top of the Start Menu that says Choose a default web browser. Click that entry to continue.
That will open up the Settings>System>Default apps area with the Web browser option selected. In the resulting pop up menu just click on your preferred browser.
Once you have selected your preferred browser it will now show as the default. Just close the window and you are done.
From this point forward any clicks on web links in apps or programs will result in your browser of choice opening up.
This is a link that 'How to set any browser as new default on Window 10'.