It always stuck at IL2CPP for more than 10 minutes. why and how to speed up the process? I have tried the examples found such as exporting to the same folder.
The WebGL build toolchain involves a number of different tools, so the build time can take a while (we're working to improve build times with IL2CPP and related toolchains now). There are a few general tips which can help improve build times here:
https://docs.unity3d.com/Manual/IL2CPP-OptimizingBuildTimes.html
Most of the build time will be spent on disk I/O in many cases, so making that as fast as possible is likely your best option.