Third conditional

If + Present Simple, .... Present Simple.

used when the result will always happen

If water reaches 100 degrees, it boils.

You get water if you mix hydrogen and oxygen.

If babies are hungry, they cry.

if + Present Simple, ... will + infinitive

used to talk about things which might happen in the future

She will miss the bus if she doesn't leave soon.

If I have enough money, I will buy some new shoes.

If it rains, I will not go to the park.

if + Past Simple, ...would + infinitive

used to talk about things in the future that are probably not going to be true

If I won the lottery, I would buy a house. _{(I probably won't win the lottery)}

used to talk about something in the present which is impossible, because it's not true

If I had his number, I would call him. _{(I don't have his number.)}

if + Past Perfect, ...would have + past participle

used to describe a situation that didn't happen, and to imagine the result of this situation

If we had taken a taxi, we wouldn't have missed the plane. _{(We didn't take a taxi.)}

She would have become a teacher if she had gone to university. _{(She didn't go to university.)}

He would have been on time for the interview if he had left the house at 10. _{(He didn't leave at 10.)}

0: IF + Present Simple, ... Present Simple

1st: IF + Present Simple, ... WILL + infinitive

2nd: IF + Past Simple, ... WOULD + infinitive

3rd: IF + Past Perfect, ... WOULD HAVE + V₃

https://www.engvid.com/learn-english-grammar-how-to-use-the-3rd-conditional/