From https://www.hostgator.com/help/article/disableenable-all-wordpress-plugins-via-the-database
Disable all plugins and the default login page will reappear.
Disable All Plugins
In cPanel:
- In the Databases section, click phpMyAdmin.
- From the left-hand navigation menu, click on the appropriate database name.
- From the left-hand navigation menu, click wp_options.
- In the options table, find the option_name column and find find the line named active_plugins. (You may have to click the > at the bottom of the page to view more columns.)
- On the active_plugins line, click edit. You will see something similar to this:
a:5:{i:0;s:35:”add-from-server/add-from-server.php”;i:1;s:25:”age-verify/age-verify.php”;i:2;s:19:”jetpack/jetpack.php”;i:4;s:69:”simple-full-screen-background-image/simple-full-screen-background.php”;i:6;s:27:”wp-super-cache/wp-cache.php”;}
- Highlight the entire box of code, cut it out and paste it into a text file to be saved on your local PC.
- Once the code has been removed, click Go.
The plugins are now successfully disabled but are still installed with all options intact.
To re-enable plugins via the database, follow the steps above and paste the code that was saved in step 5 back into the box from which it was initially removed; then click Go to save the changes.