Ebay will pass on your total sales.

They don't know what profit you have made - they just pass on figures.

Ebay no longer charge selling fees.

I believe the figure they will be passing on to HMRC is from last year, January to December 2024, so before BPF was introduced.

You can see more details from the link, but this is what Ebay will pass on:

Total number of transactions and total amount paid or credited to the seller during each quarter of the calendar year, excluding*:

• Shipping amounts paid to eBay
• VAT collected and remitted by eBay
• VAT charged on fees
• Amounts deducted by eBay for fees, coupons, cancelled or deleted orders
• Returns 

* Consequently, the amount eBay reports may differ from the total amount of payments you actually received from eBay.

https://www.ebay.co.uk/help/account/regulatory/sales-reporting/uk-digital-sales-reporting?id=5454