Calculating expenses paid for stocks

An individual can enter all charges/expenses related to buying or selling a stock in the capital loss/gain section below the total sales and purchase column. Suppose some shares were purchased in different quantites for 5 years and then sold together. Now zerodha shows the charges related only to the sales transaction and we can claim them all except the stt and the amc charges. The question is how to calculate the charges/expenses paid while purchasing these stocks? One way is to manually check the report on the date on which these stocks were purchased. Is there any easier way for people who don’t maintain any books of accounts?

This might be a stupid take but what if the charges shown in the tax pnl are doubled? But this might not work well if the prices of the stocks have increased or decreased.