TL;DR:
You want that “seed phrase”. With out it, your cash is gone. You will not discover the seed phrase in your telephone.
Coinbase declare it is a non-custodial pockets. If it really works like others, the seed phrase (often known as a restoration phrase or backup phrase) is just not saved in your IOS system and can’t be recoverd from it.
Coinbase’s assist pages say
For those who not have entry to your restoration phrase, you’ll need to create a brand new account.
Please observe: Coinbase Pockets is a user-controlled, non-custodial product. The restoration phrase is what offers you, and solely you, entry to maneuver funds that you’ve got acquired.
On your safety, Coinbase Pockets won’t ever have entry to this seed, that means that we’re unable to maneuver funds in your behalf.
If they’ve finished their job correctly, no one with entry to your telephone can get entry to your cash with out understanding the restoration phrase (or PIN). That would come with you.
One other Coinbase assist web page says
Coinbase Pockets generates a 12-word restoration phrase, additionally known as a seed phrase, that you simply and solely you’ve entry to. Because of this should you lose your restoration phrase, you’ll lose entry to your Coinbase Pockets. Please understand that Coinbase won’t ever have entry to this restoration phrase, so we can not transfer funds in your behalf or make it easier to entry your digital property.
Again up your pockets
As an added safeguard, we constructed an encrypted Google Drive and iCloud characteristic so you possibly can again up your restoration phrase. We strongly encourage you to again up your restoration phrase utilizing this characteristic, in addition to writing it down and storing it in a safe location. To entry the backup characteristic, faucet Settings then Restoration Phrase out of your Coinbase Pockets app.
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Notice that should you signal out of your Coinbase Pockets cell app you’ll be prompted to acknowledge that signing out with out your restoration phrase being backed up could end in everlasting lack of entry.
(my emphasis)