I am trying to load tickets into power bi. I am using => api/v2/tickets?updated_since=2015-01-19T02:00:00Z, as end points but it returns only last few hours data.
I am a data analyst and I need all of the tickets from the start to perform my analysis.
I think the problem you are running in to here is paging. On the first call it will return 30 tickets unless you specify the page size (max 100) and a reference to the next page in the return header. You have to keep calling until you have got everything. Read this. Freshdesk
You will need to handle the paging in Power BI: Handling paging for Power Query connectors - Power Query | Microsoft Docs