I grind a 1/8" or so off the thread part on the extension, it alows it to screw far enough to unseatthe valve core in the tire stem. Also they sell tubes that the stem makes a 90 degree where it exits the wheel.

They make air chucks that you just push up against the
valve stem, instead of clipping on. Check your auto parts
stores.

Those air chucks are nice lbpod, but they don't help. These Kobalt compressors are of a piss-pour design. I filled my tires up with a can of that goo and they've finally stayed full for awhile now.

Don't buy a Kobalt save yourself the trouble.