Answers for "how to kill 8081 port in mac"

kill process running on port mac

sudo lsof -i :3000

kill -9 <PID>

kill port from terminal on mac

sudo lsof -i :5955
ex returns: 
COMMAND  PID         USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
node    6957     someuser   28u  IPv6 0x85e555655e4ea0c3      0t0  TCP *:8091 (LISTEN)

sudo kill -9 6957