Go buy one. They're not that expensive.
That's not the problem. SOPs don't permit use of personal electronic devices in the flight deck.
The only way you can justify using one at the moment is if the EFB crashes and you need to locate information quickly... but the EFBs are so unstable, slow and difficult to use that getting to the desired resource when it's needed is a serious problem
especially on the post-fit Class II devices.
The LIDO e-route manual is a pain in the butt when trying to locate individual CRARs, not least if you need two pages at the same time e.g. Loss of comms over the pole when transitioning from Oceanic to Edmonton!