You should configure the operating system’s regional settings for non-Unicode programs.

For Windows:

Control Panel-Regional Options – Advanced Tab-Language of non-Unicode programs: you need to select your language/region

Why MetaTrader shows unknown characters and symbols instead of my language?

Go to AMarkets Official Website

For macOS

System Preferences-Language and Region – Your Language/Region

Why MetaTrader shows unknown characters and symbols instead of my language mac

Open AMarkets’ Account