DIY attempts like slapping caulk around the frame or changing surface gravel can work for minor surface splash, but they fail if the underlying issue is deep soil saturation or a blocked sub-grade drain. Professional waterproofing involves excavating down to the footing, tying into the weeping tile, and applying foundation grade sealants so water cannot bypass the barrier. You can compare methods at https://leaquida.ca/window-well-waterproofing-toronto/ to see what goes into full structural window well waterproofing. Getting it done professionally ensures you get a proper warranty and protects your basement from costly flood damage.