minecraft je json commands don't work anymore

Minecraft Java Edition 1.14.3 minecraft JSON commands /give @p written_book{"title":"old_book","author":"me","pages":["{\"text\":\"goodbye\","color\":\"red\",\"obfuscated\":true,\"click_event\":

{\"action\":\"run_command\",\"value\":\"/kill @p\"}

"]}

shows: Invalid Book tag in book_page