The function “Back to my Mac”, which made it possible under macOS to access your Mac while on the go, gets cancelled.
As Apple writes in a support document, the feature will no longer be available early next month, no matter how old your Mac is or what macOS version you are using. With “Back to my Mac” you could establish an encrypted connection to a Mac at home while on the go, preferably of course via an AirPort router. Technically you saved yourself a DDNS service with the iCloud.
No more AirPort routers, no “Back to my Mac”.
Apple no longer offers this and refers to the iCloud to share documents or normal screen sharing. Also Apple Remote Desktop is mentioned as alternative – but it costs about $90 and has not been updated for years. We therefore advise against buying it, it could happen similarly as with macOS Server.
If you can’t get along with Apple’s alternative you can also take a look at TeamViewer, a program that also allows you to remotely control other computers, for example if someone from your family needs help.