In Config file, under Misc/Boot
Change Timeout = 5 //or whatever time you need to select other boot option
Save and reboot.
At the OC boot option, use arrow key to select it. Hold down Cntrl+Enter to select MacOS as the main boot option
Need details.
You can't boot MacOS from OC picker?
You can't boot Windows from OC picker?
MacOS not showing in OC picker?
Windows not showing in OC picker?
What error are you encountering?
No idea how to help without a little bit of information than " can't dual boot"...that's pretty vague.