The process is complicated if you are overseas and wil probably end up expensive too.

I'm thinking that any UK Embassy can do the Notarising and then you have to courier stuff to the FCO in UK
https://www.gov.uk/government/world/organisations/british-consulate-general-hong-kong

A tip... After some mumbo jumbo, my Notary put his Notary stamp and embossment thing on one Notary certficate and attached all the other documents to the Notary Certificate into a kind of booklet with green tape and foldy corner thing. This cost £100 excluding travel costs to the guy, if I had every document notarised then it would have cost £600.....

Then it's couriered to the UK's FCO and I only paid one Apostille fee of £30 plus the courier fee for delivery to FCO and return back from the FCO to me - the whole episode took one week (ish).

THE FCO apostille is verfiable https://www.gov.uk/verify-apostille which cuts out any accidental leakage of your documents from a school or any recruitor to the Onanist Printing Company of no fixed abode.

Of course it's best to check what is accepted by a country's Ministry of Exploited ESOL Labor for a work permit and whether there is any "coffee money" requirement.