Hi,
It is diffucult to advise on the VAT treatment of your supplies which take place outside of the UK.
Please see the requirements for registering for VAT in the UK.
3. Working out whether you need to register
VAT is a UK and EU tax and so if you make supplies to customers outside the UK and EU then there would not be a requirement to register for VAT but you would need to contact these countries to confirm if there any other local taxes to pay.
If you are recharging a fee to your customers then the VAT would normally follow the main supply, however I would confirm this with the appropriate member state/EU MOSS guidance.
Thank you.