On the right side of the Deepnote project, you'll see a data folder, inside that you'll find the customer.csv file

Here is the direct link to the customer.csv file:

https://deepnote.com/workspace/asish-biswas-a599-b6cca607-3c12-4ae6-b54d-32861e7e9438/project/Analytic-School-8e6c85bd-e8c9-4387-ba40-0b94fb791066/%2Fdata%2Fcustomers.csv