Unfortunately at this time, I'm afraid it's not possible to mix or combine Reward points and Flexi points.
This is because Flexi points are allocated to you by your employer, but Rewards points are awarded to you on an ad-hoc basis, and can be any value that your employer chooses. If you’d like to learn more about the difference, our help article ‘How are Flexi points and Reward points different?’ may help.
You can click on the Perks hub on the left-hand panel to browse our Flexi Perks catalogue, it looks like this:
To browse our catalogue of Reward Perks, just head to the Rewards hub on the left-hand panel: