Cannot access settings after URL change

Hi Luke,
How did you try to change the site URL?
Had you move the WordPress installation folder out from the blog directory?
In this link there are some useful information about how to change the site url (edited).

Hi, I edited the two fields named “WordPress Address (URL)” and “Site Address (URL). I deleted /blog from both of these, assuming that this would mean that https://www.smackchat.org would become the webpage for my blog.

Upon doing so I lost access to my admin panel through https://www.smackchat.org/blog/wp-admin and also https://smackchat.org/wp-admin

I now can’t find a way to re-enter the /blog to the end of the two fields so that my site appears at https://smackchat.org/blog

Have you moved the entire WordPress installation out from the blog directory via FTP?

However I suggest to get it online first in the old URL (https://smackchat.org/blog).
To do so you need to edit the file wp-content/themes/twentysixteen/functions.php and add

update_option( 'siteurl', 'https://smackchat.org/blog/' );
update_option( 'home', 'https://smackchat.org/blog/' );

after the first <?php in the beginning of the file.

Or
You can edit the wp-config.php file adding `define(‘WP_HOME’,’https://smackchat.org/blog/’);
define(‘WP_SITEURL’,’https://smackchat.org/blog/’);`
right before /* That's all, stop editing! Happy blogging. */

In both methods you will override the settings you changed in the wp-admin that breaks the site, so you will be able to login in https://smackchat.org/blog/wp-admin/ and the site main url will come back to https://smackchat.org/blog/.

Let me know if you solve this first step, and sorry for my bad English..