At this time, there is no option to change the default currency of the Google Play Console account. The default currency of the Google account is based on the registered country of the user. Google Play merchant payments are in one currency only. 

The app user will pay in the currency of their home country. They cannot select the payment currency or receive payment in a currency that does not match the currency of their domestic bank account.

Should you wish to change your default currency, you will need to create another Play Console account by entering a different email address. Select the country in where the currency that they want to use is available.

Google Play Console Account creation page: https://play.google.com/console/signup

Google Account creation page: https://accounts.google.com/signup/v2/webcreateaccount?flowName=GlifWebSignIn&flowEntry=SignUp

Once done, the Google customer service team can move the apps to their new account and they will refund the original registration fee.

Link: https://support.google.com/googleplay/android-developer/answer/6230247

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