Hi everyone,
regarding the ability to trade in Europe with Tradier Brokerage (and France, Belgium for my personal situation), here is the reply of Tradier Brokerage following my request:
"Hello Romuald, Tradier Brokerage offers international accounts on a country-by-country basis. To apply for an account, please visit brokerage.tradier.com and click on the green “Open A New Account” tab in the middle of the screen. Please keep in mind that there are countries and/or territories that we are unable to do business with. These include, but are not limited to Australia, Canada and the United Kingdom. If you are a citizen and/or resident of those locales, we unfortunately would not be able to accommodate you with an account at this time. But Belgium would be fine. There is a $20 monthly fee unless you complete 2 or more trades each month."