Need to exclude specific string that could appear in multiple URLs for Azure WAF.

We use different advertisements that refer to pages on our website. When the third party puts the link on their site it modifies the URL and adds a specific string to the referring URL that is currently being blocked by Azure WAF. It is always firing on 1 rule for path traversal. I just dont want to exclude that rule from everything just when a specific text string is in the URL. This is happening for multiple URL's on our site. I dont see the option to exclude by string when dealing with URL's