Easy.

Go to My Bookings. Click on the booking. Click on the "Cabin - Fare Brand" link (e.g. Economy - Latitude). If already upgraded - good news! You cannot view the fare rules summary. They do apologize. They say the "can not", but I suspect it is more a case of "will not". Otherwise it will show you a summary of the fare rules. There is a link there "See complete fare rules". Good news! The fare rules could not be displayed at this time. They plead with you to try again later. Don't. It's all a ruse. Head over to cowtool and get the fare basis code. Google "look up fare rules using fare basis code". Descend internet rabbit hole on how to access the Amadeus API.

In all seriousness if you really want to have the true official fare rules for your flights, here is what to do, with an example.

Right after you book your flight (i.e. don't wait until just before your flight, because you want to be able to see fares that satisfy the same advance booking requirements), look up the PNR using the cowtool PNR viewer. Get the fare basis.

For example, I have a YOW-BER flight booked for the fall. The fare basis is BFFE for both the outbound and the return (of course they could be different.)

Then I head over to https://matrix.itasoftware.com/ and do a search for YOW to BER on the dates in question. In this case Sep 20 to Sep 26.

You might want to uncheck the box "Only show flights and prices with available seats" just in case you bought the last ticket with that fare basis. Click the "Show Advanced Controls" button. In the "Extension Codes" field put this (in both the outbound and the return for this example)

ac.YOW+BER.BFFE

Click on the flights you booked. (Not sure if this is necessary - maybe just click any flights.) This could take some hunting to find your actual flights.

Scroll down and find the link to the rules and there are the true, complete, official rules.