The only way to compile a .ev3 file to a .rbf file is with the "EV3 Lab" software that is not compatible with macOS 10.15 Catalina.
So your options are:
Run Windows or an older version of macOS in a virtual machine, such as VirtualBox
Find someone that can send you the compiled .rbf file, then use a tool such as ev3duder to transfer the program to the EV3.
It's possible to control a NXT with the iPhone/Smartphone although this method requires either another iPhone, Smartphone, Laptop or PC with access to the internet.
The full programming and building instructions for the 'iPhoneRobot' can be found on BattleBricks. The source code for the server application and the NXT program is also available.
It's a ...
You will have to write an application for your phone that can scan the codes and then send the information to the EV3 via bluetooth or wifi.
If you don't know how to write iOS apps, start here.
For scanning bar codes there seems to be good info here. It appears that bar code scanning is built into iOS 7. If you have an older version, the the zxing library ...
I haven't come across any existing projects like this yet, but there is nothing stopping you from doing this yourself. I would suggest writing an app for your phone in Obj-C and just remote controlling the EV3 via bluetooth.
The bluetooth communication uses the RFCOMM profile. This post might give you some hints on getting the bluetooth connection.
You can ...
Unfortunately there is no good solution for controlling NXT’s from an iPad. There are plenty of Android apps to control them manually, but you’re best bet on iOS is to write something on your own. LEGO does provide a Bluetooth Developer Kit with the info so it is possible.
I'm going to guess that USB would most likely required a jailbroken iPad. The NXT uses a custom USB protocol, so you would need raw access to the USB via IOKit.
If neither Bluetooth nor USB works, then there is no alternative other than using another computer to communicate to the NXT.