How do I click on class which have two spaces

How do I click on class which has two spaces? I am not able to click on class I tried all but nothing is working. I'm using javascript and jquery also I added dot but nothing happened**

html <div class="ad-block " id="cecd771ef93" style="margin-bottom:5px; ">

here is class

document.querySelector('.ad-block ').click()

document.getElementsByClassName('ad-block ').click();