Setting pagination extension to just plain PaginationExtension doesn't show number matched for items

[TWDBrob]

I want to be able to return numberMatched when retrieving all items. I tried swapping TokenPaginationExtension for plain PaginationExtension, but no dice. Here's what I did:

search_extensions_map = {
    "query": QueryExtension(),
    "sort": SortExtension(),
    "fields": FieldsExtension(),
    "filter": SearchFilterExtension(client=FiltersClient()),
    "pagination": PaginationExtension(),
    # "pagination": TokenPaginationExtension(),
}

...

itm_col_extensions_map = {
    "query": QueryExtension(
        conformance_classes=[QueryConformanceClasses.ITEMS],
    ),
    "sort": SortExtension(
        conformance_classes=[SortConformanceClasses.ITEMS],
    ),
    "fields": FieldsExtension(conformance_classes=[FieldsConformanceClasses.ITEMS]),
    "filter": ItemCollectionFilterExtension(client=FiltersClient()),
    "pagination": PaginationExtension(),
    # "pagination": TokenPaginationExtension(),
}

Then, when I called 0.0.0.0:8082/collections/myCollection/items, I get

{"type":"FeatureCollection", ..., "numberReturned": 10}

but numberMatched isn't there.

[vincentsarago]

did you enable the context extension in your pgstac database ?
https://stac-utils.github.io/pgstac/pgstac/#pgstac-settings-variables