# Apply Custom JavaScript

<figure><img src="/files/bypsnz8kqIdVSzsm1n0A" alt=""><figcaption></figcaption></figure>

Here, you need to provide the custom JavaScript code you would like to inject into your webpages when they are displayed through Twinr app. This feature allows you to conveniently add JavaScript Bridge commands here instead of modifying your website directly. Any JavaScript code added here will be injected into both iOS and Android apps. You can decide on which screen you want to inject it.

There are 3 types of script execution ways:

1. **Continuously**: The script will be running continuosly
2. **At Document Start**: The script will be applied when the webpage starts to load.
3. **At Document End**:  The script will be applied when the webpage is loaded fully.

You can do a whole lot of things using javascript. For example, gathering information like device info, modifying the appearance, or automating certain tasks. Please setup a meeting with us if you have any questions.

Watch video below to see how you to customize your web page by adding JavaScripts.

{% file src="/files/MlF0q1UQvsZZoiF8LeqR" %}


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://help.twinr.dev/screen-customization/apply-custom-javascript.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.