Wise (and competitors, no affiliation just can't recall other names at the moment) are popular/standard in Europe, but as far as I can tell not so much in North America. I don't know why; as far as I can tell it's supported (certainly the currencies are) and allowed?
Of course if you have cash you want sent it's no good, but I'm not sure how many legitimate use cases there are (where you can't deposit in a bank current account first) for that these days.
...what was the point of providing this answer then when the question was specifically about El Salvador...
If you do actually want to send money to an SVC denominated account in ES, then no, it doesn't help you (beyond 'you could sign up to be notified'...), sorry for bothering you with it?
We don't support SVC in El Salvador either. The USD has been our main currency since 2001.
A search for "Bitcoin price" will show the price in SVC.
The banks are literally the problem that Bitcoin solves, not the solution. Banks = fees and censorship.
But yes it is possible, and as easy as entering some different/extra numbers compared to intranational sort code/account number transfers.
Bank-bank requires that the bank at both ends supports sending/receiving to/from (as applicable) IBAN or similar yes. In the UK in practice that means 'mainstream' banks do and 'challenger' banks don't. (Monzo for example prefers to solve the problem by integrating Wise a bit into its own app.)
Wise avoids it by charging you (like paying for any other product/service) or having you transfer to its account in your country, and then sending the payment to the destination bank from its account in the same country as that, so it becomes two local transfers, one in each country.