The SIP you actually ran
XIRR solves NPV = 0 for dated cashflows. One line per event: buy negative, redemption/dividend positive. Newton can fail if every amount has the same sign.
Worked example
2021-01-01, -100000 then 2026-01-01, 160000. Rate is the annualised IRR connecting those two. Add monthly SIP lines if that is what you did.
Questions
Are my numbers uploaded?
No. Arithmetic stays in this tab. Remember writes this browser only.
Can I share the inputs?
The URL hash (#) stores fields. Copy the address bar. Nothing is sent as a query string to a server of ours.
Is this a filing?
No. Print the worksheet. Argue with payroll or a CA. Do not paste this into an ITR as authority.
Date format?
YYYY-MM-DD, amount. Negative for money you put in.
Excel mismatch?
Day-count 365.25 vs Excel’s 365 can nibble basis points. Signs wrong is the usual “#NUM!”.