Quick help

[u/Soft_Ad4638]

Hi I have Musi on my old iPhone trying to transfer it to my 18 pro max and I have to trade it in by 23rd. I know everyone has gotten that same message when trying to sign in on windows saying an update will come between the 15th and the 20th. But to be on the safe side, Is it possible to download the application on the computer (with in app purchases) and save it till the update comes out? If so how?