Please help me!

Please help me ! This is my homework but I cannot do this.
I want to this:
I will enter some information in ios app (name,surname) and ios app will save these informations on my phone csv file. is this possible ? Please help me !

To begin with, I recommend that you study the documentation for Thunkable X so that you at least have some idea of ​​what you can do with this development environment.

https://docs.thunkable.com/thunkable-cross-platform

To save information on your phone, use the Local Storage component.