I'm not sure of the question. Do you mean you want to wrap what the children of the tag into your button? if so you can get the initial content with this.innerHTML as a string and do it like so:

@controller
export class PrimaryButtonElement extends HTMLElement {
  connectedCallback(){
        const initialContent = this.innerHTML;
        const itemTemplate = (content:string) => {
           return html`<button>${content}???</button>`
        }

        this.innerHTML=''
        render(itemTemplate(initialContent), this);
   }
}

You will have to get rid of it and re-render it again.
it will render:

<primary-button data-catalyst="">
    <button>new issue???</button>
</primary-button>

I hope it helps.

I'm not sure of the question. Do you mean you want to wrap what the children of the tag into your button? if so you can get the initial content with this.innerHTML as a string and do it like so:

@controller
export class PrimaryButtonElement extends HTMLElement {
  connectedCallback(){
        const initialContent = this.innerHTML;
        const itemTemplate = (content:string) => {
           return html`<button>${content}???</button>`
        }

        this.innerHTML=''
        render(itemTemplate(initialContent), this);
   }
}

You will have to get rid of it and re-render it again. it will render:

<primary-button data-catalyst="">
    <button>new issue???</button>
</primary-button>

I hope it helps.

thanks a lot