Warning dialog box

Hello everyone I am helping a client to setup a template and they want a dialog box there, on which the user clicks on "I agree" button they are able to access the websites content after that and that should only appear one time for a user. I have got some code from chat gpt when I add the code , I can see the code is getting executed in console but when I am refreshing the page the warning box is coming back again. Has anyone done the same sort of thing in past can give me some tips on hope to achieve this and any insights @Web Bae ?
Code is in the before tag in page settings.
preview link : https://preview.webflow.com/preview/grasshopper-travels1?utm_medium=preview_link&utm_source=designer&utm_content=grasshopper-travels1&preview=226597617087a6f43295e2398aaa1a51&workflow=preview

live link : https://grasshopper-travels1.webflow.io/

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