"Too many requests" Error

While my friend was trying to play genshin, he got a "Too many requests" Error on the starting screen. The account is two days old. I helped them make the account, download genshin, all of that stuff. They have an older PC so they told me to sign onto my account first before theirs to see how it ran, it ran fine so i helped them make an account for themself. (I deleted my account log in information, they can not get onto my account from their device and i cannot get onto their account via mine) They make the account, play for two hours or so, then turn off genshin. Then they didnt play the next day. Two days after they make the account, they get a "Too many requests" error. Is it simply because of me playing on my account to see how it ran first or was someone trying to hack their account? It's only been 40ish minutes since the problem occurred which may be the problem. if anyone has tips or anything it'd be appreciated.