You can connect headphone output from your ZOOM to UR24’s inputs 3&4 using TRS to 2xTS cable. Like these ones:
https://www.sweetwater.com/store/detail/STP201
Just be careful with levels. Headphone output may have high output level which can overload UR’s input, even
though ZOOM’s technical specifications seem to indicate that this shouldn’t be a problem. If this happens just
turn ZOOM’s volume down.