We just had someone else writing in about clay in a raised bed: https://www.helpfulgardener.com/forum/vi ... =4&t=59038.
If I were filling a raised bed (and I have done in the past), I would never put any clay soil in it. Think of a raised bed as a giant container/ planter. As such, drainage is critical. Clay holds moisture, packs down, drives air out, essentially turns in to brick over time.
Peat moss by itself won't help, because peat moss is also very moisture holding. Peat moss WITH some inorganic component like perlite, coarse sand, crushed gravel, crushed lava rock, pumice will help. (Or there are organics that have some of the same qualities of staying in loose particles and breaking down slowly, promoting drainage, such as pine bark chips, rice hulls.)
If you are just talking about one bed, I would just dig the clay out and start over.