Emacs JSON update

So I managed to get the value of a key, which is in a sequence.

(alist-get
  'title
    (cdr
      (seq-elt [((_id . 6Toxj56H42yi6554j) (title . test2))] 0)
    )
)

;; Ignores the following pairs but that is fine, we only have one key, so this always hits.
(alist-get
  'title
    (cdr
      (seq-elt [((_id . 6Toxj56H42yi6554j) (title . test2) (title . test3))] 0)
    )
)

So I want to change the ‘title to set it dynamically. Going to follow up on this.