I changed the WordPress address (URL),I wasn’t able to log back

I changed the WordPress address (URL) in the General Settings page.
from: https://moraghebeh.com/meditation/
to: https://www.moraghebeh.com/meditation/
After I logged out, I wasn’t able to log back in or access the site admin to change the URL back.
the message is:
Not Found (404)
The requested URL /wp-login.php?redirect_to=http%3A%2F%2Fmoraghebeh.com%2Fmeditation%2Fwp-admin%2Findex.php was not found on this server. https://www.moraghebeh.com
How can I change it back?
thanks