I am providing services - the non-Union scheme
Do you supply services to private individuals and do you have to pay VAT in an EU country? Then you can file the VAT return in a simplified manner. Centrally. Through the One Stop Shop. Via the One Stop Shop, you file this VAT return every quarter. You pay the VAT for the different EU countries in one go. You may choose in which EU Member State you want to register.
Do you not use the non-Union scheme? Then you must contact the tax authorities of the countries where you owe VAT yourself.