Turn off the water at the shutoff valves under the sink. Remove the little red blue dot on the handle there’s an Allen key set screw to loosen to get the handle off. The important bits are underneath the handle. Sometimes the assembly just needs tightening. Other times it needs a cartridge or stem replaced. Some models you may have some seats and springs that need replacing. I don’t know what’s under that handle so I can’t be more specific. You can turn off the hot water cutoff and see if it stops, then try shutting off the cold side to see if it leaks on one side or the other. It’s a moen you could probably find a YouTube video to walk you through a “moen single handle kitchen faucet leaking” More on reddit.com

While the handle is off, spay WD40 down the stem into the bonnet. Do it with the handle over a rag to catch excess. Turn the knob while holding the bonnet. Try to free up the movement to turn smoother. May not. There might be pitted material inside. Slide the bonnet and handle over the base. Turn the knob to get it to fall into the grooves of the cartridge. Hold the handle in place, then turn bonnet to screw it back onto the base. Tighten hand tight. Turn on the faucet handle to see if the bonnet moves. If so, tighten more until it stops backing out. If you can't, then apply some silicone, but be sure you let the caulk dry before turning the handle.

More on reddit.com

If it's been stripped for some reason, it might not be a bad idea to get a set of metric hex keys around that size, if not, a flat head screwdriver with a lot of pressure and patience can usually get out a rounded hex head. After tightening, there's a good chance the handle might still be loose due to wear on the seat for the hex screw. You may need to buy a replacement part, or look at replacing the faucet. More on reddit.com

The white part is broken, you may be able to hold the stem with needle nose pliers More on reddit.com