How to actively release the memory requested through plog::inti

when i using plog in my struct, I declare the plog with plog::init(plog::debug, logFileName.c_str(), 1024 * 1024 * 1024) in construction function, but i wonder how to release the memory in my struct's destructor function
and I have tried code the destructor function with no releasing the plog memory, when I running the struct twice, the same log will write twice