Sometimes you can't remember your access key and you're locked out of your Joomla backend. No worries! Just follow one of these steps.

a) Do you have FTP access?

Go to the folder ROOT > Plugins > System and rename the folder accesskey to something else, like --accesskey. You can now enter the backend without any access key (e.g. https://www.website.com/administrator).

After logging in, go to System > Manage > Extensions, find the Access Key plugin, and uninstall it. Then go to System > Install > Extensions and install it again.

b) Do you have database access?

You can disable the Access Key plugin with this SQL query:

UPDATE #__extensions SET enabled = "0" WHERE name = "PLG_SYSTEM_ACCESSKEY"

(replace #__extensions with the database prefix your site uses, e.g. abc_extensions)

With the plugin disabled, you can enter the backend without any access key (e.g. https://www.website.com/administrator).

Go to System > Plugins > Access Key Plugin, choose a new access key, and enable the plugin again.