Be sure to check the mounting orientation (wider part of the blade down).
If screws are already present under the frame (frame protection or cable housing), use them to mount the mudguard instead of the straps.
The screws may be too short. If so, you will need to buy longer ones: M5 L20 countersunk screws.
If there is an external battery on the frame, remove it, attach the mudguard with rip-tab straps and then put it on top.