There are a few WordPress plugins that you can use to display a text banner for each post on the header. Here are a few of the most popular options:

1. Simple Banner

Simple Banner is a free and easy-to-use plugin that allows you to create and display banners at the top or bottom of your website. To create a banner for each post, you can use the following steps:

1. Go to Plugins > Add New and search for “Simple Banner”.
2. Install and activate the plugin.
3. Go to Settings > Simple Banner to create a new banner.
4. In the Banner Text field, enter the text that you want to display in the banner.
5. You can also customize the appearance of the banner by changing the colors, fonts, and other options.
6. Once you are happy with the banner, click the Publish button.

To display the banner on the header of each post, you can add the following shortcode to your post template:

[simple-banner]

2. WPFront Notification Bar

WPFront Notification Bar is another free plugin that allows you to add a banner to the header of your website. To create a banner for each post, you can use the following steps:

1. Go to Plugins > Add New and search for “WPFront Notification Bar”.
2. Install and activate the plugin.
3. Go to Settings > Notification Bar to create a new banner.
4. In the Banner Text field, enter the text that you want to display in the banner.
5. You can also customize the appearance of the banner by changing the colors, fonts, and other options.
6. Once you are happy with the banner, click the Save button.

To display the banner on the header of each post, you can enable the Display on posts option in the plugin settings.

3. Stratum – Elementor Widgets

Stratum is a premium plugin that provides a variety of widgets for Elementor, including a banner widget. To create a banner for each post, you can use the following steps:

1. Go to Plugins > Add New and search for “Stratum – Elementor Widgets”.
2. Install and activate the plugin.
3. Create a new post or edit an existing post.
4. Click the Edit with Elementor button.
5. Add a new Stratum Banner widget to the page.
6. In the Banner Text field, enter the text that you want to display in the banner.
7. You can also customize the appearance of the banner by changing the colors, fonts, and other options.
8. Once you are happy with the banner, click the Publish button.

The banner will now be displayed on the header of the post.