How to fix a 404 error on Magento Admin Page after SSL install

The CPanel solution I used resets the admin directory to its default location (at /admin/)

  1. Make sure /public_html/app/etc/env.php has the following:
'backend' => [
         'frontName' => 'admin'
     ],

2. Go into phpMyAdmin and edit the core_config_data table:
a) set admin/url/use_custom to 0
b) set admin/url/use_custom_path to 0
c) DELETE the row web/secure/base_url
d) DELETE the row web/unsecure/base_url

3. Go into fileManager and delete all the files in /var/cache

This worked for me after installing SSL, and I was able to access the /admin login page again.