hello! after how long time do i can withdraw my egld from staking in elrond app?

It's a 10 day unbonding period

You can unstake at any time. There aren't any requirements for it having been there for some time. The catch is that it takes 9 to 10 days to be able to have access to it once you've unstaked. The "unbonding period". You don't get staking rewards once you've unstaked. After the unbonding period, then you have one more button click ("finalize") for it to become available in your wallet.