where I can see the csv format guide

[lanming2023]

I have tried upload a simple test dataset, it keeps error out: 'Duplicates detected'. I have clicked the 'csv file format guide' but it redirected me to this url: https://ourworldindata.org/about#1-2-single-variable-datasets. I did not find the csv file format guide in this url page. Where can I look at format guide? For my dataset I showed below what format guide should I follow in order to upload the data.

the data is to compare different countries basel convention's scores at different years. Here is the simple dataset I upload looks like below.

it showed error after I upload dataset

[lanming2023]

I address this issue