flex justify content space between not working code example

Example 1: flexbox center and space between

//You have to give an automatic margin to all the items inside the flex.
.flexbox {
       display: flex;
       justify-content:  space-between;
    }
    
    .flex-item {
       margin: auto;
    }

Example 2: flexbox space between

justify-content: flex-start | flex-end | center | space-between | space-around | space-evenly