The dialogue between me (I) and the airline (AK), the same one that “fly airplanes” (short reference):

I: What do I need to do to go on vacation on a plane with luggage 140×70×30?

I need to:
1st Buying a plane ticket (4 sections)
2nd Ask the airline for permission to carry luggage on each section, pay extra for luggage.
But! It is not possible to give permission for every section.

What to do with tickets already purchased?

AK to give.

What if the tariff is non-refundable?

AK: Well then oh.