What to build first: Landing page or MVP?

Hey, I have been having a bit of a struggle lately to determine what should I do. In the past few weeks, I got invested in building the MVP of my idea. I already got a Figma prototype built for most of the core features, but I found it to be too rigid to try with potential users. The thing is, I received feedback from other makers to work on a landing page and "sell first". I already planned to build a landing page, but if I'm going to test and iterate, shouldn't I wait till I have a proven MVP to market? I personally want to keep building the MVP, since it *is* how to prove an idea, then do the landing page based on screenshots+videos out of it. What do you think?