Api.get_barset missing data

Hi I am trying to pull 1 min data for last one month and the code is returning only 100 rows of data. Why is there a gap? Am i doing something wrong?

Code I am using is :
history = api.get_barset(“VTVT”, timeframe=“1Min”, start = ‘2019-11-18’).df

Checked with other data source and there are data populated. Looks like a lot of data are missing.