Custom link modal doesn't update the current text but add another text with link

Hello Artur,

I'm trying to have a custom modal when clicked link button in RTE. but it doesn't convert selected text to link but what it does is it adds another text with link.

      this.editor.RichTextEditor.add('custom-link', {
        icon: '<img src="assets/images/link.png" />',
        attributes: {title: 'Link', class: 'gjs-rte-action'},
        result: rte => {
          // define what's going inside modal
          const customLinkContainer = document.createElement('div');
          const btnLink = document.createElement('button');
          const linkInputEl = document.createElement('input');
          linkInputEl.setAttribute('id', 'custom-link-input');
          linkInputEl.value = `<a class="link" href="asdf">${rte.selection()}</a>`
          btnLink.innerHTML = 'aa';
          btnLink.onclick = () => {
            const inputEl = document.getElementById('custom-link-input');
            const selectedEl = this.rte.selection();
            rte.insertHTML(`<a class="link" href="${inputEl.value}">${rte.selection()}</a>`);
            modal.close();
          };
          customLinkContainer.appendChild(linkInputEl);
          customLinkContainer.appendChild(btnLink);

         // configure modal
          modal.setTitle(t('Link'));
          modal.setContent(customLinkContainer);
          modal.open();
        }
      });

Thank you..