Can't add blocked site URL to exclusion list

I’m using Avast One. I have been trying to go to a URL that I know is safe. I’ve used this site on other devices so I know it has no malware. When I try to go to the URL, I get the warning that the site isi not safe and then I click on the button to report it. I’m told to wait 24 hours before trying again. If I try again after 24 hours, I get a “False detection reported” message.with the following: “Please try accessing the URL again after 24 hours. If we still detect it as a threat, following the instructions here or add the URL to your exclusions.” The word “here” is a link. When I click on “here”, I get a 404 not found. I want to add this site to my exclusion list. But I’ve tried waiting 24 hours 3 times and there is no way to access the exclusion list to add this URL. Documentation online posted by Avast for Avast One is wrong – it tells me to click on options that I can’t find. How do I add this to the exclusion list?