Uncaught Error: "arc" is not a registered element.

The error message “Uncaught Error: "arc" is not a registered element" indicates that you are trying to use an element (or component) in your HTML that hasn't been registered. In order to use a custom element in HTML, you need to register it with the browser. This can be done using JavaScript with the

customElements.define()

method. The customElements.define() method takes two parameters - the name of the element (arc in this case) and the class that defines it. The class should extend the HTMLElement class and contain methods and properties that define the behavior of the element. Once the element is registered with the browser, you can use it in HTML like any other standard HTML element. For example, if you wanted to register a custom element called 'arc-button' with the browser, you could use the following code:

class ArcButton extends HTMLElement {
  constructor() {
    super()
    // set up your element here
  }
  
  // other methods and properties go here
}

customElements.define('arc-button', ArcButton); 

Once the element is registered, you can use it in HTML like any other element:

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To fix the error message in this case, you simply need to register the element with the browser using the customElements.define() method.