ghost-write

/G OW1 S T R AY0 T/
verb
  1. 1

    (authorship) To write under the name of another (especially literary works).

    โ€œMariana would rather not ghostwrite for a living because she finds it a thankless task.โ€

  2. 2

    (authorship) To author a literary work or speech in the place of another.

    โ€œThe president has someone to ghostwrite his addresses.โ€

Source: https://en.wiktionary.org/wiki/ghost-write, https://en.wiktionary.org/wiki/ghostwrite