Changing server provider to Aternos, how to export modded map?

  • Hello, it's my first time posting so sorry if there's anything wrong.

    Me and my friends have a Pixelmon server, one of our friends is the host but we're thinking of switching it to Aternos instead.

    Of course, we don't want to lose our progress, so I'd like to know if there's a way to import our map to Aternos without the modded content dissapearing.

    I ask this because I tried this once a long time ago, we had a server and when we wanted to switch to Aternos, I imported the map and every modded content was gone, items, blocks, mobs, everything.

    Please help me if there's a way to import our map/server to Aternos without losing the modded content!