FOREX is not dealing with RUB at the moment because of the war in Ukraine.
Cuba's currency is the Cuban peso with the currency code CUP. One Peso is divided into 100 centavos. Cuba is a cash-is-king country. The currencies can only be bought in Cuba.
Tip! Buy Euros before you travel and exchange these for pesos in Cuba at the domestic exchange agency CADECAS. Euros are preferred to USD since there is a 10% fee for exchangeing USDs in Cuba. Card payments are accepted in many places and ATMs are available, but American travel cheques and cards are not accepted.
Delivery to nearest post agent
Save the receipt and change back for free
Buy currency in advance, no need to search for ATMs