在使用应用程序前，请先登录。

Zài shǐyòng yìngyòng chéngxù qián, qǐng xiān dēnglù.

Please log in before using the application.

你需要输入用户名和密码来登录账户。

Nǐ xūyào shūrù yònghùmíng hé mìmǎ lái dēnglù zhànghù.

You need to enter your username and password to log in to your account.

这个网站要求用户在登录后修改密码。

Zhège wǎngzhàn yāoqiú yònghù zài dēnglù hòu xiūgǎi mìmǎ.

This website requires users to change their password after logging in.