Private keys are usually not made available to the wallet owner, (although some wallets allow you to import it) rather you are given a seed phrase or recovery phrase. This is a set of words that are randomly generated and are as secure as the private keys. This phrase is used to recover your account should you use your device or wallet.
For example, red yellow green blue black brown purple grey orange indigo violet pink white
One more fact about the seed.
The seed is the sequence of words that contains the mathematical relation needed to generate all your private keys.
Private keys are not linked , but there is a mathematical relation in the private keys generated from the same seed.
If the seed leaks, all the private keys are compromised.

From mastering bitcoin book
https://www.oreilly.com/library/view/mastering-bitcoin/9781491902639/ch04.html#hd_wallets