You can set your currency in your account details page. Remember, this currency will become the default currency in your templates, proposals (which can be changed per proposal and template) and also displayed in your dashboard.
Access your Company Info details
Search Your Currency
You can search your own currency in the dropdown list.
Remember, when you update the currency at account level, it does not change/impact currencies of existing proposals and templates. You can change currency of existing proposals and templates as explained here.
This change of currency gets applicable to new proposals and templates created from scratch.