If you are using the Matomo analytics addon with uipress you will need three things to connect to the api:
Auth token
Matomo URL
Site id
Auth token
To get your auth token you can follow the below guide from matomo:
https://matomo.org/faq/general/faq_114/
Matomo URL
This is the url to your matomo installation and should look something like this:
https://yourdomain.com/analytics/matomo/
Site ID
This is the ID of the site you want to sink, if you only have one site on your matomo installation it will likely be '1' - if not you can follow the below guide on how to find your site id:
Once you have the above, you can connect and display your analytics data in the uipress overview page. When adding a matomo card, you will see the option to connect and then enter the above details.