Property ‘contentwindow’ does not exist on type ‘htmlelement’

The error “Property ‘contentWindow’ does not exist on type ‘HTMLElement'” occurs because the TypeScript compiler cannot find the property ‘contentWindow’ on the HTMLElement object. This error typically occurs when you try to access the contentWindow property on an element that is not an iframe.

The contentWindow property is specific to the HTMLIFrameElement interface, which represents an HTML iframe element. This property allows you to access the window object of the embedded content within the iframe.

To fix this error, you need to make sure that you are trying to access the contentWindow property on an iframe element and not on any other HTML element.

Here’s an example of how to fix this error:

    
      // Get iframe element
      const iframe = document.querySelector('iframe');

      if (iframe instanceof HTMLIFrameElement) {
        // Access contentWindow property
        const contentWindow = iframe.contentWindow;
        // Do something with the contentWindow object
      }
    
  

In this example, we first select the iframe element using the querySelector method. Then, we use the instanceof operator to check if the selected element is an instance of HTMLIFrameElement. If it is, we can safely access the contentWindow property on the iframe element.