How do I file a 1041 for a Trust on a mac computer? How do I file an extension for a Trust on a mac computer?

You need TurboTax Business to file Form 1041. 

Refer to the TurboTax Help article How do I file Form 1041 for an estate or trust? for more information.

You need Turbo Tax Business to do a 1041 Estate/Trust return.  

Sorry but Turbo Tax Business  is not available to do online or on a Mac.  You can probably run the Windows Business program on a Mac using a Windows Emulator like Parallels. But you would have to buy a copy of Windows to install in it.   Google Windows on Mac to get articles on the various  options.

You can buy the Window's Business Desktop program here…..

https://turbotax.intuit.com/small-business-taxes/cd-download/

Here are the system requirements to install Turbo Tax for Windows…..

https://ttlc.intuit.com/community/system-requirements/help/minimum-system-requirements-for-turbotax-windows-software/00/26175