Unique ID for Google Form that a survey respondent can see


I work for a small NGO that identifies and tracks invasive species. I am trying to solve a issue we have with tracking submitted samples. We have our volunteers and collaborators fill-out and submit a google form and that works fine. However, in order to track any physical samples that are later shipped, we would like to have a unique ID that those volunteers can see and then use when they submit the form.