If you would like to support multi-currency, navigate to Options > View Modules and select the Multi Currency Module. Check the “Enable” box if you would like to support multi-currency. Conversely, uncheck this box to disable multi-currency support. If enabled, a “Configure Module” button will appear to set your base currency.
If you are using Dynamics 365, then you may desire an extension to customize features. The extensions need to be uploaded through the Sandbox account, then it can be deployed into production from there. To upload an extension into production, open up the Extension Management screen and navigate to Manage > Upload Extension