As a vendor, you can add a store-wide notice to your store. This is a great way to advertise a sale or coupon during special events. This can be found on the Vendor Dashboard Under Settings > General.
You will have to check the enable store notice checkbox and this will display the notice box.
Once you have created the store notice and saved changes the store notice will be shown on all your vendor store pages.
Once this has been saved your store notice will appear on your store pages like below.