Dear Jade,
For that purpose you can use the REDCap Mobile App (for offline data collection):
https://projectredcap.org/software/mobile-app/
This can be easily activate by going to 
and giving you (and/or the study coordinator) access to the Mobile App:
Then a new icon will appear under "Applications":
There, you will find all the necessary documentation to install and use the App (on Ipads) and you will just have to request an API token for data transfer to happen between the Ipad device and our REDCap server database.
Best,
C.