Javascript Instanciate new Object with dynamic parameter from String

I would like to instantiate a new object with dynamic parameters coming from an exernal String.

Here is the code:

const editorInstance = new Editor('#edit',
  {
    placeholderText: null,
    theme: 'dark',
    language: 'en',
    linkList:[{text: 'test',href: 'test',target: '_blank'}],
    events: {
      initialized: function () {
        const editor = this

        this.el.closest('form').addEventListener('submit', function (e) {
          jQuery('#gs_editor_content').hide();
          jQuery(this).append('<div class="loadingDiv">&nbsp;</div>');
          o.script
        });

        texta = jQuery('#myeditor').find('textarea');
        targetFile = texta.attr('rel');
        content = editor.$oel.val();

        e.preventDefault();

        var fd = new FormData(); 
        fd.append( 'name' ,targetFile);
        fd.append( 'html', editor.$oel.val() );
        $.ajax({
          url : 'http://localhost/Update',
          type : 'POST',
          data: fd,
          processData : false,
          contentType : false,
          async : false,
          success : function(data, textStatus, request) {}
        });

        jQuery('#myeditor').dialog("close");

      }
    }
  }
})

I would need to modify the parameters linkList before instantiating my object as I receive a new list received from my server.

I tried to use eval or parseFunction but I encounter an unexpected identifier error.

any idea how I can achieve this ?

EDIT

I really need to update the parameter before creating the Object, which is not the same thing as mentioned in the question suggested as duplicate. By the way I also need to create my object after updating the parameter...

EDIT 2

I also tried to simply include my var containing the String but it doesn't work:

var dropdownFiles = "[{text: 'test',href: 'test',target: '_blank'}]";
const editorInstance = new Editor('#edit',
  {
    placeholderText: null,
    theme: 'dark',
    language: 'en',
    linkList:dropdownFiles,
    events: {
    .....

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