CMD is opening 2 windows (CMD and JAVA)

Hello, i did a lot of changes on my paper server, but i do not know what i did wrong that caused to this second window to appear, i opened dozens of diferent server on my PC on the last 3 years and none of them had open this second window, can someone tell what to do? Everytime that i open my server this second window apear, how do i disable this?

Add --nogui behind your JVM flags.

what do you mean by “behind”? On the beggining of the flag? This is my flag

java -Xmx16G -Xms16G -jar paper.jar nogui

are you sure? adding nogui like that should be fine. please double check that thats actually the content of the file you are running