I tried, but needed an American phone number and American address to register. Any Americans have success? What exchange did you use?

I used Coinsmart behind a VPN.  It is Canadian.  But it may accept Americans?  I used my sister's Canadian address and I entered my Korean phone number to get a confirmation text.  I used interact e transfer but that is a Canadian thing.  Will it accept a debit or credit card for deposit if you are American?  Canadians are banned from using their debit or credit card.  If you still have an American bank account to link to it could work.  I did sign up for Coinbase a long time ago and can't remember what I used which was American but also global. 

A lot of Canadian banks don't allow you to use their cards to buy Crapto, unfortunately.

Yeah.  It sucks but a loophole is interac e transfer.  Coinsmart logged into and registered via VPN you can do that.  I put some money on it as I mentioned before.  Sent it over to FTX from there BTC wallet transfer.  Then converted to other cryptos.

Unrelated but similar situation, PayPal finally let me register my Korean cell number even though everything else on it is Canadian including accounts address, etc.  Was always a pain before when I got locked out.  Had to call during their Canadian business hours.  So, that's fixed too.  Great to see many sites accepting Korean cell phone numbers. 

Another riveting probably ignorant childish comment I"ll never read above this one I am sure.  Can't read it. 

Anyways, I just found out Coinsquare bought Coinsmart.  So, maybe better to go with them if you are Canadian and still have your bank open back home.  They also do Interac E - Transfer.  If you are American, Coinbase and others are there for you and I think you can still fund with your US debit or credit card. 

Worse case scenario if you trust a family member, perhaps you could send them some money and get them to put some crypto on for you?  Then do a BTC wallet to BTC Wallet transfer on another exchange like FTX. 

But, I may recommend opening a bank account the next time you go home and use a relative that you trust mailing address?  Just tell the bank you moved back from Korea and also sign up for online banking.  (For those of you who closed your bank accounts when you left.)  Besides you will need to send home severance and other moneys and a wire transfer to your home bank is easier anyways in the future.  If you are Canadian and more than 6 or 7 years have gone by if you defaulted on your student loans they should be gone off your credit report.  (Just open with a different bank than the one you were opriginally with if you did this.  I never defaulted myself.) 

As for banks, I use two.  RBC seems to accept only Canadian phone numbers for verification online though you can choose security questions.  TD Bank seems more globally minded and will accept your Korean cell number for verification while still using a Canadian address.  (I use my sisters address, but they do keep my Korean address on file so they do know I am a resident here.  Hence why my credit card limits have not been increased in years, but still high enough.) 

For the record, this is just for a bank account, I doubt they will issue credit cards or anything like that though.  As I said before, sign up for online banking at the same time when you go into the branch.  Bring some ID with you.  Social number, driver's licence or state or provincial ID?  Long term this will make life easier for many of you going forward.  Just get the lowest service fee package available since you won't be using many debits or atm withdrawls.  Maybe you can get by with 3 or 4 dollars a month.  It is an expense but a small one.  Worth it keep an account open for money transfers, funding crypto, etc.  With TD you can even open a trading account, though you will have to register your Korean address every 3 years due to the US SEC regulations.  Need to fill out a W-BEN form or something like that?  (Hard to do some of this stuff in Korea unless you have a Korean wife to do it for you.  Same for funding crypto here.) 

Anyways, something to think about.