combining apple ID accounts

I have an original Apple ID account (20+ years old) and had issues with recent IOS updates. APPLE SUPPORT told me the old APPLE ID account was the problem because of some old account linking that APPLE did back in the 1990s. SO APPLE support had me create a new APPLE ID. However that causes me problems with accessing some paid for APPS (sharing is not feasible). I am also now paying for 2 extra storage accounts. I recently learned that 2 accounts CAN BE COMBINED —- that coming from an APPLE executive at a recent conference. SO APPLE SUPPORT how do I combine my two accounts