Want to change site url of wordpress site

Hi,
I want to change site URL of my WordPress application. My WordPress application is inside ‘public_html/blog’ that’s why URL of my application ‘https://www.example.com/blog’, but I want application web URL should be like https://www.example.com and I don’t want to change wp files location, all files and folders should be on same location in side /blog folder, only want to change browser URL. I tried to change the site url in Dashboard settings and in wp-config.php, but not working giving ‘HTTP 500 error’.
Please help me.
Thanks.