json data in CURL code example

Example 1: curl post json

curl -X POST -H "Content-Type: application/json" \
 -d '{"username":"abc","password":"abc"}' \
 https://api.example.com/v2/login

Example 2: curl post json

curl -d '{"key1":"value1", "key2":"value2"}' -H "Content-Type: application/json" -X POST http://localhost:3000/data