Currency exchange

i have a question pls my question goes like this “if a country pegs its currency with another one say cedi/usd what if a firm or maybe an individal from outside the shores of Ghana with usd currency wants to buy cocoa from them where will he or she exhange the usd, will he carry the usd down to ghana to exchange it at thier exchange rate counter or is thier any place in his country say united states where he can change it and they will give him or her cedi” thats my question good day friends

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