how to make an item float on the complete left and the other item on the complete right in flexbox code example

Example 1: flexbox css

.container {
  justify-content: flex-start | flex-end | center | space-between | space-around | space-evenly | start | end | left | right ... + safe | unsafe;
}

Example 2: css flex

.container {
  display: flex; /* or inline-flex */
}