Speaking from personal experience, your best option would be Over-The-Counter Market (OTC) , or at least this is how things used to be when I was in Malaysia , there are a lot of miners there and they always seek to sell their bitcoin to pay power bills or get their "Nasi Lemak" , Telegram,Facebook etc.. is where you can meet those people, in fact even websites like mudah.my can help you find good sources.
and of course, I can't stress enough on how many scammers are there, so make sure you do your own due diligence and always try to have a face-to-face transaction in public places like a mall or a bank.
keep in mind that it's very unlikely that you are going to find any source who does 100% market price, you usually have to pay 0.5-2% above market price, depending on the quantity, in extreme cases where your order is really large, you could even buy bitcoin for a little discount, but in general it will cost you less than all the other suggestions.
Never tried on OTC in Malaysia, only through some close friends. Other than that, i usually have to use Remitano for the quickest way to cash out from crypto.
I guest still a long way for crypto-to-fiat conversion in Malaysia.