Why does create not automatically create the id for Event? Does anyone have an idea why the following would return Error: Cannot return null for non-nullable field Event.id ?

const res = async ( root, args, ctx ) => await ctx.prisma.updateUser({
        where: {id: promoter.id},
        data: { 
          promotions: { 
            create: [{ ...event }]
          }
        }
      })
return res;