Player name from NBT tag to procedure parameter

Please help! It is necessary to execute a command when sending a redstone signal to a block. It seems to be a simple task, but I can’t configure who this command will be distributed to. I created a block, added the “privacy” function to it. When you right-click on a block, it is assigned a text NBT tag with the player’s nickname. How in the name of all that is holy can I extract the nickname from the NBT and add it to the “name” parameter of the command?