First make an item, and then make a procedure for when right clicked in air and make a switch dimension for provided (entity)player to ID [ID]. The ID is the ID for your dimension. You can find it by selecting your dimension in MCreator and pressing the edit mod element IDs and registry names just to the right of the localization on the middle left. The ID will be the ID you see + 2. This changes in MCreator 2019.5, where you can simply scroll down this procedure block for a list of dimensions.
First make an item, and then make a procedure for when right clicked in air and make a switch dimension for provided (entity)player to ID [ID]. The ID is the ID for your dimension. You can find it by selecting your dimension in MCreator and pressing the edit mod element IDs and registry names just to the right of the localization on the middle left. The ID will be the ID you see + 2. This changes in MCreator 2019.5, where you can simply scroll down this procedure block for a list of dimensions.