Template Dropdown not showing up within Wordpress administrator page

Question

I am working on a Wordpress-based project, and I just added a new template to the installation by uploading a template file. I was creating a new page that will use my new templ

Answer 1

This was also a problem for me and it was because of folder structure. The Theme Handbook told me a should organize my theme folder and files like so:

assets (dir)
    - css (dir)
    - images (dir)
    - js (dir)
inc (dir)
template-parts (dir)
    - footer (dir)
    - header (dir)
    - navigation (dir)
    - page (dir)
    - post (dir)
404.php
archive.php
comments.php
footer.php
front-page.php
function.php
header.php
index.php
page.php
README.txt
rtl.css
screenshot.png
search.php
searchform.php
sidebar.php
single.php
style.php

The page template I was trying to load was in /template-parts/page/template-contactus.php

I guess that was too deep for WordPress so I got ride of those directories and now my file structure looks like this:

assets (dir)
    - css (dir)
    - images (dir)
    - js (dir)
inc (dir)
template-parts (dir)
    - section-content.php
    - template-contactus.php
404.php
archive.php
comments.php
footer.php
front-page.php
function.php
header.php
index.php
page.php
README.txt
rtl.css
screenshot.png
search.php
searchform.php
sidebar.php
single.php
style.php

I am now able to see the template drop-down and add templates.

Hope this helps someone.