html js how to post code example

Example 1: javascript send post

var xhr = new XMLHttpRequest();
xhr.open("POST", yourUrl, true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(JSON.stringify({
    value: value
}));

Example 2: post method javascript code

const postData = async ( url = '', data = {})=>{
    console.log(data);
      const response = await fetch(url, {
      method: 'POST', 
      credentials: 'same-origin',
      headers: {
          'Content-Type': 'application/json',
      },
     // Body data type must match "Content-Type" header        
      body: JSON.stringify(data), 
    });

      try {
        const newData = await response.json();
        console.log(newData);
        return newData;
      }catch(error) {
      console.log("error", error);
      }
  }