What cable do I need to use 2013 iMac in target display mode?

I have a 2013 iMac (not retina) that’s gotten pretty sluggish. I would love to use it as a second screen for my 2016 MacBook, which only has a USB-C port.

1) Is this possible with the computers I have? (Googling seems to suggest yes, but I’m not the most tech savvy.)

2) Which port do I need?

Both computers are used lightly. Their main tasks are Google docs and watching YouTube videos, and a Zoom happy hour once a week.