Manipulate elements into a selected block in command

How can I manipulate elements into a block content?

For example: My block:

bm.add('img-text', {
    label: 'Image + Text',
    content: {
        type: 'img-text',
        content: '<table class="table"><tr><td style="width:50%;height:100%"><img style="width:100%;height:100%" /></td><td style="width:50%;height:100%"><span>Text<span></td></tr></table>'
    }
});

My component:

domComps.addType('img-text', {
  // Define the Model
  model: defaultType.model.extend({
        defaults:{
            tagName: "div",
            type: "",
            name: "",
            removable: !0,
            draggable: !0,
            droppable: !0,
            badgable: !0,
            stylable: !0,
            "stylable-require": "",
            unstylable: "",
            highlightable: !0,
            copyable: 0,
            resizable: !1,
            editable: !0,
            layerable: !0,
            selectable: !0,
            hoverable: !0,
            void: !1,
            state: "",
            status: "",
            content: "",
            icon: "",
            style: "",
            attributes: "",
            classes: "",
            script: "",
            traits: ["id", "title"],
            propagate: "",
            toolbar: null
        },
  }
  ),
  // Define the View
  view: defaultType.view.extend({
            events: {
            'click': function(){
                    var openSmBtn = editor.Panels.getButton('views', 'options');
                    openSmBtn.set('active', 1);
            }
        },
    })
});

Command:

editor.Commands.add('options', {
    run: function(editor, sender){
        const myContent = document.createElement('div');
        var myText = editor.getSelected().find('span');
        // Here I'm tring to change Text content
        myText.set('content', 'New Content');
        var myImg = editor.find('img')
        const button = document.createElement('input');
        button.type = "button";
        button.className = "btn btn-success";
        button.style = "margin-top:10px";
        button.value = "Add a Image";
        button.onclick = function () {
            editor.runCommand("open-assets", {
                // Here I'm tring to trigger assets toimg
                target: myImg,
                onSelect: function () {
                    editor.Modal.close(), editor.AssetManager.setTarget(null)
                }
            });
        };
        myContent.appendChild(botao);
    }
});