Get all bookmark IDs from Word Document - ms-word

Question

I want to scan an entire document containing text with the styles Heading 1, Heading 2, normal text and several bullet points / other text (which is basically a tech report). After scanning I want to extract bookmarks assigned to "Heading 2" elements, which also act as sub heading titles within the report.
getBookmarks() is defined in the Preview / Beta API which works if my cursor is placed on the "Heading 2" element, as seen below:
async function getBookmarks() {
Word.run(function(context) {
var range = context.document.getSelection();
var bkmrk = range.getBookmarks(true, true);
return context.sync().then(function() {
console.log("The bookmarks read from the document was: " + bkmrk.value);
});
}).catch(function(error) {
console.log("Error: " + JSON.stringify(error));
if (error instanceof OfficeExtension.Error) {
console.log("Debug info: " + JSON.stringify(error.debugInfo));
}
});
}
I've managed to scan the entire document and obtain the "style" attribute as well, as seen from the example code on API documentation:
async function getParagraphAll() { await Word.run(async (context) => {
// Gets the complete sentence (as range) associated with the insertion point.
let paragraphs = context.document.body.paragraphs
paragraphs.load("text, style");
await context.sync();
// Expands the range to the end of the paragraph to get all the complete sentences.
let completeParagraph = paragraphs.items[0]
.getRange()
.expandTo(
context.document
.getSelection()
.paragraphs.getFirst()
.getRange("End")
)
paragraphs.load("text, style, hyperlink");
await context.sync();
for (let i = 0; i < paragraphs.items.length; i++) {
console.log(paragraphs.items[i].style);
//let range = paragraphs.items[i].getRange() - Why is this not working ?
//let bkmrk = range.getBookmarks(true, false) - This doesnt get me the bookmark while its in
//the loop scanning the entire document. Is it because it fails on "Normal" style?
// Should I filter out "Normal" and only run "getBookmarks" on "Heading" style ?
console.log(paragraphs.items[i].style);
} }); }
I've made the reference to Libraries available in the preview API link: https://appsforoffice.microsoft.com/lib/beta/hosted/office.js
I'm struggling to understand why I can get the bookmark at cursor level but when I want to get it for the entire document, it just displays
do context.sync() before loading any property. There is no need for
load.