If you can't find your Clickbank receipt in your emails (maybe it's in your spam/promotions folder, search for "Clickbank" in your spam/promotions folder), try this:
1. Visit the Look Up Your Order page on Clickbank: https://www.clkbank.com/#orderLookup
2. Around the middle of the page it says Order Lookup. Click on the "I don't have my order number" link
3. Fill in the fields as they require
4. You will get a verification email from Clickbank.
5. Once you log in to Clickbank with the instructions from the email, look for your purchase to find the receipt in your order history. From there you should be able to recover your order, then get the link to log in to the member's area.
If you have any issues with the above, please get in touch with Clickbank support by using their "Live Chat Now" button near the top of the page (https://www.clkbank.com/#orderLookup) and explain to them that you need help recovering your purchase receipt.