We often partner with NQE's (training flight schools) to provide discounted cover for your flight assessment. It may be worth contacting your training instructor as they will give you a unique promo code which you can enter into the app.
Once you've received your promo code, just click on 'I have a referral code', enter the code and hit 'Save Changes'.
When booking your insurance with your code, you'll be asked to enter your payment details. Don't worry, you won't be charged! It's just for verification purposes
Below is a GIF that demonstrates how to do this nicely (please note the code below is not a valid discount code, it is simply used for demonstration purposes):