I’ve never used Stripe – but if you check their invoices, do they show a UK (GB prefixed) VAT registration number, or a foreign one?
If it’s a GB number, then it’s possible that their services may fall within a VAT exemption (unlikely to be covered by a zero rating).   See HMRC VAT Notice 701/49:  https://www.gov.uk/government/publications/vat-notice-70149-finance 
If the nature of the services aren’t covered by this exemption and Stripe are only established overseas, you’ll need to do the reverse charge.