Player object text components do not render as player faces when used inside written_book, but as black squares.
Use :
/give @s minecraft:written_book
Then :
/item modify entity Lordphenex weapon.mainhand {function:"minecraft:set_written_book_pages",pages:[[{player:{name:"jeb_"}},{player:{name:"jeb_"}},{player:{name:"jeb_"}},{player:{name:"jeb_"}},{player:{name:"jeb_"}}]],mode:"replace_all"}
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