This is a mod that allows you to implement a black screen quiet function for players in the game, and it has been open-sourced on GitHub.
You can use the command /black <players> (seconds) (text) (textColor) (backgroundColor) to apply the black screen quiet effect to selected players. When the black screen quiet effect is active, players will not be able to press any keys and will not be able to close the interface on their own. The text displayed during the black screen quiet effect, as well as its color and background color, can be customized. The displayed text can use the “|” symbol for line breaks. This command requires an OP (Operator) level of 2.
If you want to remove the black screen quiet effect from someone, you can use the command /end-black <players> to解除 the black screen quiet effect for that person. This command also requires an OP (Operator) level of 2.
