Hello, What is the correct way to merge users before login and after, so that experiment variation will not change for the user after he logs in, in our use case, users might use the app before signing in. we set the ID in our frontend like this while using Growthbooks DeviceID

gb. setAttributes ({
id: currentUser?._id ?? deviceld,
deviceld: deviceId,
utmSource: Cookie.get ('utm_source'),
utmMedium: Cookie.get ( 'utm_medium'),
utmCampaign: Cookie.get ('utm_campaign'),
utmContent: Cookie-get ('utm_content'),
}) ;
}, [currentUser, isInitializedl);

Hi Invai