post requests 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 https post

curl -d "" https://example.com

curl -H "Content-Type: application/json" --data "@C:\Users\xxx\Desktop\body.json" https://example.com/api/service