Usually we use the setup wizard to congure "LAN Routing":
I want to do the same but whit powershell, but I can't find how.
Any ideas to do this automatically without using wizard?
There are some details missing from the question, like what Windows version, but this feels like a reasonable question to ask (doesn't seem like it's asking for a script writing service, just how to get past the initial configuration), especially since you can run RRAS on Server Core and not have the wizard locally at all.
In any event, assuming Windows Server 2012 R2 or later, the initial setup is mentioned in passing at https://docs.microsoft.com/en-us/windows-server/remote/remote-access/remote-access#bkmk_rras, namely to use
Install-RemoteAccess as more fomally documented at https://docs.microsoft.com/en-us/powershell/module/remoteaccess/install-remoteaccess?view=win10-ps, for example:
Install-RemoteAccess -VpnType RoutingOnly
remoteaccess module is documented at https://docs.microsoft.com/en-us/powershell/module/remoteaccess/?view=win10-ps. The exact parameters to it will depend on what you want to do with RRAS, of course.
After that, it's up to you to do the rest of the configuration steps, as that seems out of scope of the original question.