i have mongodb community installed on mac but i cant run it code example

Example 1: brew services start mongodb

//Starts Mongdb server @ mongodb://127.0.0.1:27017/
brew services start mongodb-community@4.2

//Stops Mongdb server @ mongodb://127.0.0.1:27017/
brew services stop mongodb-community@4.2

//mongo
mongo - starts the mongo client

Example 2: mongodb installation on mac

//Starts Mongdb server @ mongodb://127.0.0.1:27017/
brew services start mongodb-community@4.2
mongod --config /usr/local/etc/mongod.conf --fork
ps aux | grep -v grep | grep mongod
mongo