The Armenian dram (AMD) is the national currency. Exchange points are found on almost every street in Yerevan, and besides dollars and euros they constantly handle Russian rubles, Georgian lari and Iranian rials. There are also offers in Gyumri, Vanadzor, Abovyan and Hrazdan.
Rates are posted on boards outside each exchange point and can differ noticeably between neighbours, so it pays to compare them on the map. P2P offers help you swap USDT or USDC for drams or receive a transfer from abroad.