Learning how to use 得 to mean "must" must be done by those wishing to master Chinese!
Structure
Normally when you see 得 it's a particle and is pronounced "de". However, it can also be an auxiliary verb. In this case it's pronounced děi and means "must".
subject+得+verb+object
Examples
Shíjiān bù zǎo le, wǒ dé huí jiā le.
时间 不早了，我 得 回 家 了。
时间 不早了，我 得 回 家 了。
It's getting late.I have to go home.
