Short answer: Try the typical recruitment websites.

Long answer: most important step is definitely locking in on your target firm: Fintech related? Public Sector related? Gaining sector insights is also useful

Then try to network with the founder/ HR before you propose working as an intern for them

During chitchats (if they are nice enough to respond), ask politely when they are expecting to hire a new intern and show that you are passionate

Not a good idea to straight up ask: hi mate, nice to meet you, care to hire me?

Also consider whether you would accept a no-pay offer.

Startup intern唔易有posting，但唔知點解問開啲founders個個都話想要interns😂

你呢個做法絕對可以一試，因為近幾個月多subsidy scheme俾startup請interns，不過通常都係tech role多；又或者可以試試inbox佢啲social media channels (if any)，但至緊要唔好太mass msg，otherwise感覺唔良好🤔