libcsnd-dev 1:6.13.0~dfsg-3 (amd64 binary) in ubuntu focal

 This package contains the development files needed to build programs
 using the C++ bindings to the Csound library. It also includes the
 development symlink for the lua module, but you have to manually
 install liblua5.1-luacsnd for that to work.
 .
 For more information on Csound, see the csound package.