Have you looked at the documentation tab on the marketplace page?
https://marketplace.mendix.com/link/component/111393
There's also more specific information about the API here:
https://developer.salesforce.com/docs/atlas.en-us.api_rest.meta/api_rest/intro_what_is_rest_api.htm
If you're getting stuck at a specific point, can you show us? We can give you some more specific help then.