Error 401 in creating post using rest-api

I am trying to use Basic Auth using username / password and I am getting below error which i see in rest api logs. I tried both Java based and Node JS based client. My user is Admin and have whole access. I am able to read the post but creating post have the problem.

{
“data”: {
“code”: “rest_cannot_create”,
“message”: “Sorry, you are not allowed to create posts as this user.”,
“data”: {
“status”: 401
}
},
“headers”: {
“Allow”: “GET”
},
“status”: 401
}