> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.popup-builder.com/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# How to Install a Single Extension

There are two ways to extend the Popup Builder plugin by purchasing: 

* A Single Extension
* The [Bundle](https://help.popup-builder.com/en/article/how-to-install-bundle-paid-version-3364s5/) (includes all the extensions)

This article will help you install a **Single Extension**.

| It is not possible to install an extension unless the core plugin is installed beforehand. So you will need to install the [Popup Builder core plugin](/en/article/how-to-install-the-popup-builder-plugin-1hoof9z/) first.

#### Steps to purchase a single extension

1.  Go to Popup-Builder website, press on **"Extensions"** button or simply open [this link](https://popup-builder.com/extensions/).

2. After choosing the preferred extension, press on **"Add to Cart"** then on **"Checkout"** buttons. 

3. You will be redirected to the checkout page. From there, fill in the required fields and finalize the payment for the single extension.

**Also see the gif below in order to visualize the steps**


![](https://storage.crisp.chat/users/helpdesk/website/3fee58eaeb6dda00/single-4_121pafw.gif)

### Steps to install the purchased extension 

1. Once the purchase is done, the system will automatically create a new account for you. So, click on the **"My Account"** button.

2. You will see the extension name and a downloadable .zip file under the **Download **button. Press on it to download the .zip file.

We took the Subscription Plus extension as an example


![](https://storage.crisp.chat/users/helpdesk/website/3fee58eaeb6dda00/my-account-popup-builder-1_16loz0u.png)

3. Once the .zip file is downloaded go to your WordPress account, click on **Plugins**, after **''Add new''** and **''Upload Plugin''** buttons.

![](https://storage.crisp.chat/users/helpdesk/website/3fee58eaeb6dda00/image-blur_e6cgks.png)

4. Choose the .zip file downloaded beforehand and upload it.

5. When the upload is over, click on the **"Install Now"** and then the **"Activate Plugin"** buttons.

You are all set up!

 **Here is the gif to visualize the steps**



![](https://storage.crisp.chat/users/helpdesk/website/3fee58eaeb6dda00/single-6_17wjv4k.gif)


| Once all the steps are complete, you can activate the license for you to get updates and support  [like this](/en/article/how-to-activate-license-keys-5cjni3/).