I have a div with some children:
heading 1
heading 2
Some
Not sure about flexbox but you can do using the position property.
set parent div position: relative
and child element which might be an or etc.. set position: absolute and bottom: 0.
Example:
index.html
Child
style.css
.parent {
background: gray;
width: 10%;
height: 100px;
position: relative;
}
p {
position: absolute;
bottom: 0;
}
Code pen here.