Connect Rest API with user authentication and line limit per request

Hi

I´m trying to connect to the next API using Blank Query but it’s been more complex that I thought

On the next lines the API info:  

Method: GET Path: https://api.repsly.com/v3/export/clients/{lastTimestamp}

Accept: application/json, application/xml

Content-Type: application/json, application/xml

User: 804144F2-78E3-47DE-9CCB-9B226634CD91

Password: 3B5A34D3-AD6D-496E-9125-4CAD9F8FXXXX

In each call the Api sends 50 lines - data base is no less than 600 lines.

To get the first set of data I change the {lastTimestamp} for a 0 as the next example https://api.repsly.com/v3/export/clients/0 

On the next lines a short description on how I the Metadata must be implemented:

"In every response you will receive meta variable LastTimeStamp of the last changed record in the list. Save it for future requests so you can use it as a parameter {lastTimeStamp} for every subsequent request until the response meta variable TotalCount is equal to 0, which means you have received all updates.   To get the complete list of clients, start your request with parameter {lastTimeStamp} = 0.  

Any help will be more than apreciated!!!