 All 11th generation Intel CPUs are locked against undervolting.  No software exists to do the job, period.  
Hope all of you're doing great. I want to undervolt my recently bought Inspiron 15 3511 with i3 1115G4 as my laptop gets hot after I use it for a while. Undervolting the i3 6100 of my desktop made it much cooler. However, I could not install XTU, the latest version (7.8.1.20) of which showed that the laptop CPU was unsupported. Can I install XTU somehow or is there other supported alternatives for this? I heard of Throttlestop but not sure if using that is okay. I'd still prefer XTU if I can install it as I'm used to it.
CPU (i3 1115G4) Undervolt