Noted That:

• To install correctly this post-thumbnail-extras.zip .
• Fisrt Download the post-thumbnail-extras.zip to your computer
• Extract/Open post-thumbnail-extras.zip to Your Computer.
• Then, Find readme.txt file inside post-thumbnail-extras.zip and Open readme.txt .
• Now, Read the Requirements of this plugin. Which Wordpress Version and PHP Version are required to run this Plugin in Your Wordpress Site.
• Then, Follow the Tips Below.

Start the Tips:

1. First Download " post-thumbnail-extras.zip " Plugin to your Local Computer. (Click Download)

2. Then, Login to your " yourdomain.com/wp-admin " Dashboard.

3. Then, Click on " Plugins " + " Add New " from left sidemenu of Dashboard.

4. Now, Click on "Upload Plugin" button.

5. Now, Browse " post-thumbnail-extras.zip "  Downloaded plugin from your computer, Where you downloaded post-thumbnail-extras.zip According to Step – 1 Above then, click on " Install Now"

6. Now, Click on " Active Plugin"

7. Then, See left sidemenu. " Post Thumbnail Extras " folder is added on left sidemenu. Now, Click on " Post Thumbnail Extras " folder.

   Noted that: If you do not see " Post Thumbnail Extras " folder on left sidemenu then, see at left sidemenu " Settings " or " Tools ".

8. Now you configure yourself oR Watch video tutorial below about  Post Thumbnail Extras Configurtions and Settings or How to work " Post Thumbnail Extras " in your WordPress site.

After Activated Plugin According to Step-6 then,

1. Go to " Plugins " + " Installed Plugin " from Wordpress Admin Panel Leftside Menu.
2. or Direct go to: https://yourdomain/wp-admin/plugins.php
3. Then, Find " Post Thumbnail Extras " Activated Plugin from Plugin List.
4. Then, Click on " Settings " from Plugin that is Post Thumbnail Extras
5. Now, Edit/Add/Config the setting and Click on " Save Changes " button,

Shortcode

Use the shortcode [pt] in your posts to quickly embed the featured image as a thumbnail. Use the attribute ‘size’ to change to a different post-thumbnail size (e.g. [pt size='medium'] ). You can also use any image in your media gallery if you know the id, by using the id attribute ( [pt id='100'] ).

Use the link attribute to wrap the image in a link.

• link='file' will create a link to the full size image.
• link='post' will create a link to the attachment page.
• link='http...' creates a link to any URL.

Use the media library to quickly add this shortcode for the selected image by pressing the “Insert shortcode” button.

Add/Delete Post Thumbnails

1. In Settings ? Media, click the plus sign to add a new post thumbnail.
2. Update the width/height and whether or not the post-thumbnail should be cropped to an exact size. (If the width or height is set to 0, that boundary constraint is not enforced — effectively, it’s infinite). Make sure you click the “save” button so that the changes are stored in the database.