how to position items inside css grid?

I’m learning the CSS grid and trying to position the items inside grid?

can get and see data from javascript:

const profileImg = document.createElement('img');
var profilePhotoUrl = post.user.get("photo").url();
profileImg.src = profilePhotoUrl;
profileImg.className = "profile";

const username = document.createElement('username');
username.className = "user";
username.innerText = post.name;
const content = document.querySelector('.content'); 
content.append(profileImg, username);

from CSS

body {
    display: grid;
    margin: 0;
    grid-template-columns: 20% auto;
    grid-template-rows: 60px auto 100px;
    grid-template-areas: 
        "header header"
        "sidebar content"
        "sidebar footer";
}
.content {
    grid-area: content;
    justify-self: center;
}

and it looks like this. how can I position them vertically?
(profile username) <–like this
(profile username)
(profile username)