The Magento_WebapiSecurity module enables access management of some Web API resources.
If checkbox enabled in backend through:
Stores -> Configuration -> Services -> Magento Web API -> Web Api Security then the security of all the services outlined in
app/code/Magento/WebapiSecurity/etc/di.xml would be loosened. You may modify this list to customize which services should follow this behavior.
By loosening the security, these services would allow access anonymously (by anyone).
Before installing this module, note that the Magento_WebapiSecurity is dependent on the following modules:
For information about enabling or disabling a module, see Enable or disable modules.