Send a POST request to => http://localhost:4000/api/v1/dialog-flow
postBody = {
    sessionId: /*EXPRESS SESSION ID*/,
    query: /*USER MESSAGE TEXT*/,
    contexts: /*CONTEXT FROM PREVIOUS GOOGLE REPLIES*/
}
let postBody = {
    sessionId: /*EXPRESS SESSION ID*/,
    query: /*USER MESSAGE TEXT*/,
    contexts: /*CONTEXT FROM PREVIOUS GOOGLE REPLIES*/
};
postBody = JSON.stringify(postBody);
const url = 'http://localhost:4000/api/v1/dialog-flow';
fetch(url, {
    method: 'POST',
    body: postBody,
    headers: {
        "Content-Type": "application/json"
    }
})
.then(data => data.json())
.then(data => {
    /* ADD RESPONSE TEXT TO MESSAGE BOX AND SAVE CONTEXT IF CONTEXT EXISTS */
})