How to add back arrow in NavigationUi prpject

I've started to create my project made by an Activity, with Nav Drawer, NavigationUi who call two fragments and also three Activities. After a lot of errors, I understand a lot about Navigation. I understand that I need to use instead of calls, in navigation, and also include the proper navigation of the activity. Also I've found to set back arrow from second activity to first, but here i found a hurdles. Activity Main, call secondary activity, in appbar I found arrow. This second actuvity have a bottomnavbar, but after first time that is changed fragment, I loose back arrow. I think is normal because I'm inside a standalone Activity, wirh her navbar, but I ask, is possible to implement an arrow with a callback to Main Activity? I think is possible, as the back button in the bottom of smartphone, but how? TKS for your kind answers!