Noted That:

• To install correctly this h5p-css-editor.zip .
• Fisrt Download the h5p-css-editor.zip to your computer
• Extract/Open h5p-css-editor.zip to Your Computer.
• Then, Find readme.txt file inside h5p-css-editor.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 " h5p-css-editor.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 " h5p-css-editor.zip "  Downloaded plugin from your computer, Where you downloaded h5p-css-editor.zip According to Step – 1 Above then, click on " Install Now"

6. Now, Click on " Active Plugin"

7. Then, See left sidemenu. " H5P CSS Editor " folder is added on left sidemenu. Now, Click on " H5P CSS Editor " folder.

   Noted that: If you do not see " H5P CSS Editor " folder on left sidemenu then, see at left sidemenu " Settings " or " Tools ".

8. Now you configure yourself oR Watch video tutorial below about  H5P CSS Editor Configurtions and Settings or How to work " H5P CSS Editor " 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 " H5P CSS Editor " Activated Plugin from Plugin List.
4. Then, Click on " Settings " from Plugin that is H5P CSS Editor
5. Now, Edit/Add/Config the setting and Click on " Save Changes " button,

From the WordPress plugin menu click on Add New and search for H5P CSS Editor

Instead of searching for a plugin you can directly upload the plugin zip file by clicking on Upload:

Use the browse button to select the plugin zip file that was downloaded, then click on Install Now. The plugin will be uploaded to your blog and installed. It can then be activated.