Keep previous query load

I am loading data from the web. The source gives me the last 100 days of data, but I want to build an archive, so that in each refresh I add the last 100 days, but I keep whatever I loaded in the previous refresh, and simply discard duplicates.

In Excel I could do this:

Query A: Web import, and append of Query B, loaded into Excel (Table1).

Query B: Load from Table 1. Connection only.

First time query A gets 100 days of data, appends Query B (empty at this stage, and loads into the table1.

In 5 days time, I run again. I get 100 days of new data, I append 100 rows from Query B, and remove duplicates. I am left with 105 rows, and I load that into Table1. And so on.

How can something similar be done in PowerBI desktop?

Thanks in advance!