Recording Live Concerts from Soundboard (Macbook 2012)

Hey there, new to the forum. Decided to sign in after discovering and reading on here that my Mac was built with out the option for input on the headphone jack. So I have an external sound card for home recording but I am looking for the easiest way to use my mac to record live shows. I could use te external sound card but I would like a direct input option as the more equipment the more impatient sound guys can be.

So I am wondering if you guys have any advice. I know the imic is an option. What about an rca to usb recorded with logic? I don't know, if anyone has solved this problem I would love to hear what you did. I am hoping to not have to buy a bunch of things for trial and error...

thanks 🙂