You need to pay VISA fees, sometimes to the embassy/VISA centre or to Campus France or to the both.
Price : around €100 but depends on each country
A VISA is required for a non-European Union citizen, staying more than 3 months in France.
Without it you can’t come in France. Embassies are very strict about the file that must been complete. If you get one refusal, it’s really hard to have a second chance.
The process depends on each country. Feel Parisien explains you the process regarding the country where you do the request and double check your documents before you give them.