Hey there. You don't 'need' any Dreambane piece until you reach the final mission in the Shadowkeep campaign, 'Beyond'. When you reach that, you can reacquire lost pieces from Eris. If you are on any earlier step, you do not need to wear any Dreambane pieces at all to progress. Just carry on with the campaign and get any missing pieces from Eris just before the end. If the Lectern is not accessible, then you're probably up to Nightmare of Omnigul, step 5. Is that right? Note some people read the text and think they need a full set right then and there, but it is talking about the pyramid, you're not going there yet, that's the end quest. Moreover at that stage in the campaign, you've only unlocked the class item. This however gets reinforced by a bug that can happen if you enter the Nightmare of Omnigul mission too quickly, like on a Sparrow. It causes a certain ogre not to spawn, an ogre whose death removes the barrier leading further inside. That can lead people to think it is linked to Dreambane pieces, but it is not. Just walk into the area instead and the ogre should spawn.