An article and video on how to make dovetail keys for corners.
https://www.woodsmith.com/newsletter/2021/01/14/making-dovetail-keys-at-the-router-table/?utm_medium=email&_hsmi=106246662&_hsenc=p2ANqtz-9tsc7Aa_zdXnlVKgtQ_SMbhjy7_QOcVS6JEz84gFoxcI25OxV9I-aK45l6VxJxbIJDZFKChBqIkw85JyjB2HEowjoGZzAL47WneQFpJ-IOuOfvA9A&utm_content=106246662&utm_source=hs_email