TestCafe: problem with specifying selector: span to grab text

I would like to grab the text from span but I have a problem with pointing this selector.

I tried defined it following:

1. this.channelName = Selector('span[class="scheduler-header__service-name"]'); or
2. this.channelName = Selector('div').find('#schedule').find('.scheduler-header').find('.scheduler-header__service-name')

And I always received information:

“Cannot obtain information about the node because the specified selector does not match any node in the DOM tree.”

Could somebody declare this selector for me?