I am afraid there is no such thing as "mining from your phone".

They will ask you to send them your passport (KYC) to transfer your "coins" from the "testnet" to "mainnet".
There are so many meaningless words in the above sentence within the Pi project, but the most important is that they have 0 reason for KYC, other than collecting millions of passport photos and sell them on the dark web.
Millions will suffer from impersonation...