Generally, Western countries (let’s consider Singapore as Western for now) provide scholarships to graduate students studying science and engineering (especially science).

Science is difficult to study but the pay is not high. Westerners generally study it only if they are bookworms with a "dedication spirit".

Therefore, scholarships may be more likely to be given to foreigners.

Intermediaries generally try to trick you into getting money out of you.

Scholarship agencies cannot be hacked.

Since you want to study for a regular graduate degree, you can DIY it. You can go to an agency for consultation, but it is not advisable to leave it all to the agency.