Alternating page margins (mirror pages), manipulating headers/footers with page numbers

Question

I am trying to output a Word document using a formatted company reference_doc.

The issues are that:

1. The document should be in book format with mirror margins: alternating left/right margins on odd and even pages.
2. The footer should include page numbers (right aligned on odd pages and left aligned on odd pages) and author’s name on odd pages and document title on even pages.
3. Page numbers should appear first on page 6.

Intended margins and footer format

So is my yaml front matter:

---
title: "Document Title"
author: "Author Name"
output: 
  officedown::rdocx_document:
    reference_docx: reference_doc.docx
  page_size:
    width: 6.18
    height: 8.78
    orient: "portrait"
  page_margins:
    bottom: 0.87
    top: 0.71
    right: 0.87
    left: 0.98
    header: 0.49
    footer: 0.24
    gutter: 0

---

Using fpar and prop_section functions in Officer/Officedown packages, I have been about to produce different text in footer on odd and even pages, but I have no idea how I can add page numbers.

knitr::opts_chunk$set(echo = FALSE, fig.cap = TRUE)
library(officedown)
library(officer)

right_template <- function(txt) {
  block_list(
    fpar(values = txt,
         fp_p = fp_par(text.align = "right", padding.top = 0, 
                                     padding.bottom = 22, padding.right = 13), 
         fp_t = fp_text_lite(font.size = 9, font.family = "Trade Gothic Next",
                                           color = "black", bold = FALSE) 
         )
  )
}

left_template <- function(txt) {
  block_list(
    fpar(values = txt,
         fp_p = fp_par(text.align = "left", padding.top = 0, 
                                     padding.bottom = 22, padding.left = 13), 
         fp_t = fp_text_lite(font.size = 9, font.family = "Trade Gothic Next",
                                           color = "black", bold = FALSE) 
         )
  ) 
}
sec_pr <- prop_section(
    page_size (width = 6.18 , height = 8.78, orient = "portrait"),
  page_mar(
    top = 0.71,
    bottom = 0.98,
    left = 0.98,
    right = 0.71,
    header = 0.49,
    footer = 0.24,
    gutter = 0.0),

  footer_default = left_template("Author Name"),
  footer_even = right_template("Document Title")
)

Do you have any idea how I can produce mirror (alternating) margins and add page numbers? I can share the reference_doc if needed.

I have tried to first set (mirror) margins and edit the footer in the reference_doc, but when I knit, (the output Word has all the styles as per reference_doc) the footer is empty and the margins are default.