How to update my already uploaded excel sheet whenever a user finishes their test

Here is the context, I am making a test to calibrate the difficulty of my question set via IRT hence I will need multiple students to do the test. I have created a UI and used shinyapps.io for them to access it on their own computers.

Problem now is I need to update a sheet called testee_responses that i have already upload into shinyapps. It should populate whether the testee gets the question right or wrong (binary 1/0) for each question but since its via shinyapps, it doesnt get populated. Is there a solution for this?

Thank you for your time, do let me know if you need further clarifications

You are running into a problem of persistent storage: when someone opens your app on shinyapps.io, they get a copy of everything you uploaded, including that Excel sheet. When they close their browser, that copy is destroyed and the next user gets a fresh copy of everything. This is important to avoid someone uploading a virus into your app for example.

There are many ways around it,a simple one is to create a Google Sheet with your Google account, and have the Shiny app add data to it using {googlesheets4}. That way the Shiny app itself does not need to store data between session, the Google sheet is there for long-term, "persistent", storage.