I was going to add a promotion banner on only product page but it wasn't solved. i have found this app (Quick Announcement Bar) after a few hours.
Great Plugin. Thank you to everyone who made this app.

Very straightforward and easy to use. Not hard to understand at all. 10/10 would definitely recommend.

Love this plugin and love the customer service. I asked a bunch of questions and got responses right away

This app has been an essential tool in our effort to communicate inventory and shipping challenges caused by Covid-related demand spikes over the past year. Thanks to the developers for providing such a great little app!

Simple to use and does the job! Highly recommended for anyone who wants a quick solution and user-friendly way to inform customers.

I am just coming to grips with the possibilities. So far seems easy to use even for a novice like myself. Works in real time!

I love how easy it is to use this Quick Announcement Bar app to notify my website visitors of our best current deals or important policy changes. I've been using this app for years.

Grateful for the free plan. Does the job! I wanted an announcement bar I could customise and this app gives me the control I wanted :)

Very easy to use, I submitted review before seeing what the banner looks like but I am sure it will be great.

I love how simple and easy it is to use this app. I love that there is a free version and I'm still able to do customize the banner colors to fit my brand.