How to save data in user's MS Teams instance?

I have created a Teams bot application, which needs to save data received from users. I am currently using azure cloud storage for that, but now as the client requested I want to save the data in the user's MS teams instance. I am collecting birthdate and joining date from the team members and storing it in azure storage, but as it's personal data clients don't want it to be saved remotely instead they want to save it in their team's instance. What are my possible options?