As a fresh grad that is specialise in digital marketing , how many internship i should apply in order to get a full time job in digital marketing ? hope to hear some thoughts and advice thanks.

You will never know for sure, depends on how you do at the interview and how you 'market' your unique strengths, rem that companies will wan to get the best person for their budget, but us, we need to secure the best pay for our skillsets.

There's no magic number actually. Just apply and give it a try, if you get it then good, if not then perhaps you can try starting out with contract roles - something to get cashflow in before going full-time.