How do new nations get their currency recognized.?

Question

how do they get it recognized so foreigners can visit and exchange money as well as get foreign banks to set up cash machines so they get money out of machines

Answer 1

Things like national debt / Government borrowing (bonds), convertible currency, diplomatic relations & all other such entitlements etc. come with 'recognition' of the (break-away) state as a 'Sovereign Nation'

If you don't get 'recognised' then you don't get any of the above