Is “The official history records Emperor Xian granting a secret edict in a garment belt, while the novel adds the plot of writing the secret edict in blood.” true?

The Records of the Three Kingdoms, Book of Shu, Biography of the Former Lord records that Emperor Xian issued a secret edict to kill Cao Cao, only mentioning 'he received the secret edict in the emperor's garment belt, and should kill Duke Cao.' It does not mention a blood letter. However, in Romance of the Three Kingdoms, Chapter 20, to dramatize Emperor Xian's sorrow and determination, it adds the plot of biting a finger to write a blood letter: 'The emperor then composed a secret edict, bit his fingertip, and wrote it in blood, secretly ordering Empress Fu to sew it into the lining of a jade belt and purple brocade.' The novel dramatizes based on historical facts.