Yes—Canon’s own EF extenders generally won’t mount to the 100mm f/2.8L Macro because their front element protrudes and requires compatible lenses with a matching rear clearance.

A third-party teleconverter can work, since some brands such as Kenko, Tamron, or Soligor use a design without that protruding front section. A teleconverter increases effective focal length, which can let you keep the same framing/magnification from farther away, though you lose light and may affect autofocus performance and image quality.

Another reported option is using a Canon 2x extender in a setup that also includes extension tubes. That combination is often used to increase maximum magnification, but it can also help you reach a given magnification with more working distance.

So in short: Canon extenders usually aren’t a direct fit on that macro lens, but compatible third-party teleconverters may be a practical way to gain more working distance.