Revolut has partnered with Qover, an untied insurance agent, for the provision of this service. The insurance policy is issued by Qover, and Qover will take care of all the documents regarding the insurance.
The insurance is provided by Wakam or Chubb depending on your residence country.
Please see the Terms & Conditions in the app for more details.
You can access them in the app by going to Marketplace → Insurance → select the type and click on 'All documents'.