You may be able to use a GUI object, or make it part of the participant info. See here: Fail to pass url parameters
However, your recruitment platform (Prolific, MTurk, etc.) might offer you a better solution. For example, if you are using MTurk, you can contact all workers who participated in a given study, or create qualifications such that only those who participated in one study can participate in another. CloudResearch, which acts as a sort of add-on for MTurk, can automate this.