The combinations has got and have got are idioms that
mean has or have. They can also be used with to. When
they're used in this way, they mean the same as has to
and have to ( = "must" or "be required to"):

It's late! I've got to leave!

Mehmet can't come to the party. He's got to work.

Your grades aren't very good. You've got to work harder.

Tell Angela she's got to be ready in 10 minutes.

Don't forget that we've got to meet Mr. Brown
at 5:00 PM.

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Special Note:

Has got to and have got to are almost always
contracted to 's got to and 've got to. The "got to"
part of each combination is pronounced something
like "godda" in everyday speech. Also, the 've is
often not pronounced or pronounced very weakly,
so you might hear something that sounds like "I gotta
go" or "You gotta help me" or "We gotta hurry."

Important: "Gotta" is for speaking, not for writing!