I'm trying to POST my local storage to an API, but everytime I do it, I get a status: 400. Title of error says '"One or more validation errors occurred."'

I must be doing this wrong. I'm trying to loop through all the key value pairs and then send that via a POST.

Code:
  public postInfo() {
    for (let i = 0; i < localStorage.length; i++) {
      const key = localStorage.key(i);
...