lIke wayne said its not OEM sunroof,
there will be a catch on the handle somewhere, you can then lift out the glass completely & clean the seals........ they will have shrunk, and or perished...... aftermarket sunroofs are notorious for leaking,
try lifting it out & cleaning it all up, if it still leaks after that, take the glass out again & put sikaflex around them, then carefully put the glass back in........... It will glue the sunroof shut but if done right it will stop the leak........