Selenium cannot find element with class name

I want to make a crawler to gather some information from a website. I’m using Python and Selenium for this purpose. The problem is that elements cannot be found with class names but can be found using XPATH. The code that I’m using for this is as bellow:

HTML:

<h1 class="txt-h4 clr-900 lf-2">
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</h1>

Selenium XPATH: (Working Solution)

product_name = driver.find_element(By.XPATH, "/html/body/div[1]/div[1]/div[3]/div[3]/div[2]/div[2]/div[2]/div[1]/div/h1").text.strip()

Selenium CLASS NAME: (Not working solution)

product_name = driver.find_element(By.CLASS_NAME, "txt-h4 clr-900 lf-2").text.strip()

I also tried this approach using beautifulsoup4, but the result was same with class names:

product_name = page_soup.find("h1", {"class":['txt-h4 clr-900 lf-2']}).text.strip()

The error that I get with this solution is:

AttributeError: 'NoneType' object has no attribute 'text'

What I need to do is to be able to locate elements by class name because of granularity.