Nepal Relief Banner

One line of HTML puts that strip at the top of this page on your site, linking to the Government of Nepal Prime Minister's Disaster Relief Fund. 

<script
  src="https://cdn.jsdelivr.net/gh/clashrelated/nepal-relief-banner@1.0.2/banner.min.js"
  integrity="sha384-zsV61Tmn6kfxMnauiuGMOgbTqBC6qhHBy/x0ne2M0sSSoK3q+xTlPs3ZMC8W/SUp"
  crossorigin="anonymous"
></script>

Paste it after your opening <body> tag. 3.2 KB gzipped, no requests of its own, no branding, and it takes itself down on 30 September.

Try it

data-positiontop sits above your content and scrolls away with it. sticky does the same but then holds at the top of the screen. bottom is pinned to the bottom of the viewport. If your site already has a sticky header, use top or bottom, or the two will fight over the same strip of screen.
data-themelight, dark, or auto.
data-langen, ne, or auto, which reads your <html lang>.
data-accentCompatibility alias for data-link and data-icon.
data-bgAny CSS colour, for the background.
data-iconAny CSS colour, for the icon.
data-linkAny CSS colour, for the link.
data-underlineAny CSS colour, for the underline.
data-ruleAny CSS colour, for the bottom border.
data-dismissiblefalse drops the close button.
data-analyticsauto forwards the donate click into your gtag or dataLayer. Off by default.
data-untilThe last day it shows, Nepal time. A bare date runs through the end of that day. Past it the script renders nothing.
data-targetA CSS selector to mount into instead of the page edge.