reflex/docs/library/layout/spacer.md

components
rx.radix.spacer

import reflex as rx

Spacer

Creates an adjustable, empty space that can be used to tune the spacing between child elements within flex.

rx.flex(
    rx.center(rx.text("Example"), bg="lightblue"),
    rx.spacer(),
    rx.center(rx.text("Example"), bg="lightgreen"),
    rx.spacer(),
    rx.center(rx.text("Example"), bg="salmon"),
    width="100%",
)

As stack, vstack and hstack are all built from flex, it is possible to also use spacer inside of these components.