Talk to Urologist on Urine 5hiaa Test Protocols

My Dr recommend me 24 hours urine for 5HIAA Test, I am not in contact with Dr but following my 3 day protocol

I want to know what 3 days actually means, like should I avoid described food items medicines etc for 2 days and then I have to collect sample ?

or

should I avoid described items for 72 hours and then start collecting sample ? so they'll be total 96 hours of abstain