I have a world with some mods but it is a bit buggy and I would like to transfer some items that I got there to another world because I didn't want to start all over again but I didn't find any way to export items from the inventory
like in the terraria that you create a character and you can move between their worlds with his items
--I used google translator to write this I ask for forgiveness for any possible error
The only mod I know that can allow items to be moved from world to world is Not Enough Items (as it allows for saving inventory presets) but otherwise nothing really does this (not sure if it's similar to Terraria the way NEI does it either). That or I just have never come across a mod that allows for inventory crossover otherwise.
Not Enough Items was a recipe/cheating and more mod for many years before Just Enough Items up until 1.8 but from 1.9.4 onwards (I think currently up to 1.12.2) it is an addon for JEI that includes the same Inventory, the viewing things in the world and features JEI doesn't have but keeping JEI's existing features. So just add NEI and CodeChickenLib to a 1.12.2 environment and you'll be fine.
Edit: I'd actually recommend majestyc2k1's suggestion by just looking at the player's inventory/stats/location data and moving that to the world folder of the world you want to play in.