Steps to change site URL without visual login panel:

Step 1: SSH Log into The Site

local$ ssh username@ip-address

Step 2: Edit Configuration Manually

server$ nano path-to-wordpress/wp-config.php

(In the case of DigitalOcean, it’ll be “var/www/html/wp-config.php”). Use keyboard to navigate down to the bunch of “define”s, add these 2 lines in their midst, and this time put the right URL in:

define('WP_HOME','http://example.com');
define('WP_SITEURL','http://example.com');

Exit and save file by Ctrl+X.

Step 3: Profit

Voilà! Your admin panel is back to normal.

Reference:

• https://codex.wordpress.org/Changing_The_Site_URL