Why does PyMupdf Document show the error, no attribute 'new_page', when it is a PDF?

I’m working on annotating a PDF and I want to change its color. I was guided to this helpful link: https://pymupdf.readthedocs.io/en/latest/faq.html#how-to-add-and-modify-annotations

I used the code in the link:

# -*- coding: utf-8 -*-
"""
-------------------------------------------------------------------------------
Demo script showing how annotations can be added to a PDF using PyMuPDF.

It contains the following annotation types:
Caret, Text, FreeText, text markers (underline, strike-out, highlight,
squiggle), Circle, Square, Line, PolyLine, Polygon, FileAttachment, Stamp
and Redaction.
There is some effort to vary appearances by adding colors, line ends,
opacity, rotation, dashed lines, etc.

Dependencies
------------
PyMuPDF v1.17.0
-------------------------------------------------------------------------------
"""
from __future__ import print_function

import gc
import sys

import fitz

print(fitz.__doc__)
if fitz.VersionBind.split(".") < ["1", "17", "0"]:
    sys.exit("PyMuPDF v1.17.0+ is needed.")

gc.set_debug(gc.DEBUG_UNCOLLECTABLE)

highlight = "this text is highlighted"
underline = "this text is underlined"
strikeout = "this text is striked out"
squiggled = "this text is zigzag-underlined"
red = (1, 0, 0)
blue = (0, 0, 1)
gold = (1, 1, 0)
green = (0, 1, 0)

displ = fitz.Rect(0, 50, 0, 50)
r = fitz.Rect(72, 72, 220, 100)
t1 = u"têxt üsès Lätiñ charß,nEUR: €, mu: µ, super scripts: ²³!"


def print_descr(annot):
    """Print a short description to the right of each annot rect."""
    annot.parent.insert_text(
        annot.rect.br + (10, -5), "%s annotation" % annot.type[1], color=red
    )


doc = fitz.open()
page = doc.new_page()

page.set_rotation(0)

annot = page.add_caret_annot(r.tl)
print_descr(annot)

r = r + displ
annot = page.add_freetext_annot(
    r,
    t1,
    fontsize=10,
    rotate=90,
    text_color=blue,
    fill_color=gold,
    align=fitz.TEXT_ALIGN_CENTER,
)
annot.set_border(width=0.3, dashes=[2])
annot.update(text_color=blue, fill_color=gold)
print_descr(annot)

r = annot.rect + displ
annot = page.add_text_annot(r.tl, t1)
print_descr(annot)

# Adding text marker annotations:
# first insert a unique text, then search for it, then mark it
pos = annot.rect.tl + displ.tl
page.insert_text(
    pos,  # insertion point
    highlight,  # inserted text
    morph=(pos, fitz.Matrix(-5)),  # rotate around insertion point
)
rl = page.search_for(highlight, quads=True)  # need a quad b/o tilted text
annot = page.add_highlight_annot(rl[0])
print_descr(annot)

pos = annot.rect.bl  # next insertion point
page.insert_text(pos, underline, morph=(pos, fitz.Matrix(-10)))
rl = page.search_for(underline, quads=True)
annot = page.add_underline_annot(rl[0])
print_descr(annot)

pos = annot.rect.bl
page.insert_text(pos, strikeout, morph=(pos, fitz.Matrix(-15)))
rl = page.search_for(strikeout, quads=True)
annot = page.add_strikeout_annot(rl[0])
print_descr(annot)

pos = annot.rect.bl
page.insert_text(pos, squiggled, morph=(pos, fitz.Matrix(-20)))
rl = page.search_for(squiggled, quads=True)
annot = page.add_squiggly_annot(rl[0])
print_descr(annot)

pos = annot.rect.bl
r = fitz.Rect(pos, pos.x + 75, pos.y + 35) + (0, 20, 0, 20)
annot = page.add_polyline_annot([r.bl, r.tr, r.br, r.tl])  # 'Polyline'
annot.set_border(width=0.3, dashes=[2])
annot.set_colors(stroke=blue, fill=green)
annot.set_line_ends(fitz.PDF_ANNOT_LE_CLOSED_ARROW, fitz.PDF_ANNOT_LE_R_CLOSED_ARROW)
annot.update(fill_color=(1, 1, 0))
print_descr(annot)

r += displ
annot = page.add_polygon_annot([r.bl, r.tr, r.br, r.tl])  # 'Polygon'
annot.set_border(width=0.3, dashes=[2])
annot.set_colors(stroke=blue, fill=gold)
annot.set_line_ends(fitz.PDF_ANNOT_LE_DIAMOND, fitz.PDF_ANNOT_LE_CIRCLE)
annot.update()
print_descr(annot)

r += displ
annot = page.add_line_annot(r.tr, r.bl)  # 'Line'
annot.set_border(width=0.3, dashes=[2])
annot.set_colors(stroke=blue, fill=gold)
annot.set_line_ends(fitz.PDF_ANNOT_LE_DIAMOND, fitz.PDF_ANNOT_LE_CIRCLE)
annot.update()
print_descr(annot)

r += displ
annot = page.add_rect_annot(r)  # 'Square'
annot.set_border(width=1, dashes=[1, 2])
annot.set_colors(stroke=blue, fill=gold)
annot.update(opacity=0.5)
print_descr(annot)

r += displ
annot = page.add_circle_annot(r)  # 'Circle'
annot.set_border(width=0.3, dashes=[2])
annot.set_colors(stroke=blue, fill=gold)
annot.update()
print_descr(annot)

r += displ
annot = page.add_file_annot(
    r.tl, b"just anything for testing", "testdata.txt"  # 'FileAttachment'
)
print_descr(annot)  # annot.rect

r += displ
annot = page.add_stamp_annot(r, stamp=10)  # 'Stamp'
annot.set_colors(stroke=green)
annot.update()
print_descr(annot)

r += displ + (0, 0, 50, 10)
rc = page.insert_textbox(
    r,
    "This content will be removed upon applying the redaction.",
    color=blue,
    align=fitz.TEXT_ALIGN_CENTER,
)
annot = page.add_redact_annot(r)
print_descr(annot)

doc.save(__file__.replace(".py", "-%i.pdf" % page.rotation), deflate=True)

And I keep running into this error:

AttributeError: 'Document' object has no attribute 'new_page'

I’ve tried it on a few other PDFs and it does not seem to work, however, PYMUDF documentation https://pymupdf.readthedocs.io/en/latest/document.html#Document.new_page describes that it should have this attribute.

How do I enable a new page to be inserted to remove this error?