RenderTexture is not working in canvas base

I did some code here

this._iconSprite = GameAsset.icons[id];
        this._iconSprite.x = (this.symbolWidth - this._iconSprite.width) / 2;
        this._iconSprite.y = (this.symbolHeight - this._iconSprite.height) / 2 - offset;
        this._renderer.render(this._iconSprite, this._renderTexture, true);