First try adjusting the mix valve settin. It’s similar for most, but look up a video for your specific brand. Generally you remove the handle (loosen the set screw and pull it off the valve stem) and then there’s a toothed ring with a stop. You pull the ring forward, turn it to permit the handle to rotate further (i.e. more hot water is allowed) and push it back in the new location. Temporarily slide the handle back on and rotate it to see if you get more heat. If not, repeat and try again. Make sure you set it so it can’t be turned too hot, to protect children or guests from scalding themselves. Once it’s set where you want, tighten the set screw again.