Nuxt/docs/content/3.api/1.composables/set-layout.md

setPageLayout

setPageLayout allows you to dynamically change the layout of a page. It relies on access to the Nuxt context and can only be called within components' setup functions, plugins, and route middleware.

export default defineNuxtRouteMiddleware((to) => {
  // Set the layout on the route you are navigating _to_
  setPageLayout('other')
})

::alert{icon=👉} If you choose to set the layout dynamically on the server side, you must do so before the layout is rendered by Vue (that is, within a plugin or route middleware) to avoid a hydration mismatch. ::