Hi there @Cavite
Usually, most apps or websites will only ask you for a one-time password when you sign in on a new device (or browser) for the first time. After that, they'll generally only ask you for your password, although there are some exceptions to this. As someone who's used Gmail for almost as long as it's been around, I know that in my experience, I've only ever had to use two-factor authentication (such as a one-time password) when signing in on a new device, or a new browser, or if I'm browsing incognito. Otherwise, my password is enough to let me in, since the device or browser is now trusted.
Hope that helps. :)
— Grey