The following process works with all WordPress versions after version 3.7. Alas, turning off Automatic Background Updates is strongly discouraged.
Disabling Automatic Background Updates via wp-config.php
Once more, this is STRONGLY DISCOURAGED. We’d much rather have you enable automatic background updates for major releases of WordPress core!
Per WordPress:
The core developers made a conscious decision to enable automatic updates for minor releases and translation files out of the box. Going forward, this will be one of the best ways to guarantee your site stays up to date and secure and, as such, disabling these updates is strongly discouraged.
Navigate to your root WordPress directory (in this case: /home/example/public_html) and edit the wp-config.php file:
vim wp-config.php
or
vim /home/example/public_html/wp-config.php
Add the following to the file:
/* Disable Automatic Background Updates for WordPress */
define( ‘AUTOMATIC_UPDATER_DISABLED’, true );
In this case, I added the above code just above:
/* That’s all, stop editing! Happy blogging. */
Then exit and save the file with the command :wq .