Assuming that you mean that "if the browser" has a specific cookie. This is fairly simple.
On your Data Layer tab, add the cookie as a data source.
2. type is cookie value
Once the cookie is defined in the Data Layer tab, then it is available as a Data Source in the Load Rule builder.
When creating your load rule, you could either use "is defined" (if all you care about is that the cookie is present) or use one of the other conditions (such as equals) to trigger the load rule on a specific value.
Don't forget to publish your changes for them to take effect!
Hope that helps.
You can do the following:
1) Create a new data source and give it the same name as the cookie. Make sure the name matches exactly (i.e. if the cookie is called "testCookie", then the data source must also be called "testCookie").
2) Set the Data Source type to "Cookie Value"
3) In your load rule, select the new data source as the basis for your condition.
Hope this helps.
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