Remote setup
LS Retail hosts the online help on a public server at https://help.lscentral.lsretail.com.
To add the LS Central help website to the Help & Support page in Business Central, set the BaseHelpUrl in navsettings.json to https://help.lscentral.lsretail.com as described in https://docs.microsoft.com/en-us/dynamics365/business-central/dev-itpro/deployment/configure-help#online-library
Local setup
Note: As of version 18.0, the Microsoft Dynamics 365 Business Central Help Server has been discontinued. The Business Central online help is available via links on the LS Central Home page and side navigation menu, and directly via this link.