have to

I’ve to do lots of things today.
I have to do lots of things today.

I haven’t to earn a lot of money to be happy.
I don’t have to earn a lot of money to be happy.

Have you to get up early tomorrow?
Do you have to get up early tomorrow?

In have to, have is a main verb, not an auxiliary verb.

We do not normally contract it in affirmative sentences: I have to, not I’ve to.

Use do/does in questions and don’t/doesn’t in negative sentences.

Don’t have to means that something is not necessary: ‘You don’t have to come if you are busy.’

With have got to, we can contract have: ‘I’ve got to leave now.’