Terminal hangs while writing into a FIFO file

I have a program running under a systemd service and I'd like to pass some text/commands to it, so I tried doing so with a FIFO file:
.service file

[Unit]
Description=A Minecraft server service!

[Service]
EnvironmentFile=/etc/systemd/system/minecraft.env
WorkingDirectory=/srv/http/mc/mcserver/
ExecStart=/srv/http/mc/mcserver/start  minecraft_input or echo 'stop (or anything)' | tee minecraft_input)` it just hangs with no output and nothing gets passed. (FIFO File created using mkfifo and has permissions 664)

EDIT:

I accidentally pasted the wrong code. I also tried this:

.service file

[Unit] Description=A Minecraft server service! Requires=minecraft.socket [Service] EnvironmentFile=/etc/systemd/system/minecraft.env WorkingDirectory=/srv/http/mc/mcserver/ ExecStart=/srv/http/mc/mcserver/start StandardOutput=append:/srv/http/mc/mcserver/mcserver.log StandartInput=socket [Install] WantedBy=multi-user.target

.socket file

[Socket] ListenFIFO=/srv/http/mc/mcserver/minecraft_input Service=minecraft.service [Install] WantedBy=sockets.target ``` But that doesn't work either. The echo command completes, but nothing happens/passes to the program.