Adding this method to your SysSingleton and marking it with Eco.ExternalLateBound=anyvalue can give you access to the running Turnkey system's URL address:
Making the method "IsQuery" makes it available in OCL (not only action language) - and you can write things like this:
...this will fully qualify the address to a report template found in SiteAssets.
Or maybe you need a QRImage with a fully qualified URL back to your system:
Please note that this is the URL of the TurnKeyserver. Thus, an action originating from TurnKey needs to set the URL. This action may be necessary to persist the address for server-side jobs or SysAsync tickets running on MDrivenServer.
Note that this function (and all ExternalLateBound ) are only available at the TunrkeyLevel - not the MDrivenServer level.
Maybe you searched for GetServerUrl - but the name is GetSystemUrl (Leave this for better indexing).
Additional methods ExternalLateBound method on SysSingelton
Additional methods ExternalLateBound method on SysSingelton as SHA512ComputeHash, SHA256ComputeHash and BitConverterToString are found here: SHA512ComputeHash, SHA256ComputeHash and BitConverterToString