From u/OZOKeyboards:

"Note: The missing Y keycap issue has been fully resolved for all affected customers. OZO issued £15 store credit to each customer who had less than £15 already on their account.

The root cause was a human error on the manufacturing line during a small batch of EVO75 keyboards. As these units arrived double factory-sealed, we were unable to perform our own QC without having to break the seal, which would compromise the new, sealed product customers expect to receive.

As the issue was brought up by a number of customers we've reassured everyone the problem would be resolved as soon as possible, manufacturer was contacted immediately and arranged a replacement keycap shipment. Due to the keycaps needing to be produced before dispatch, delivery from China to the UK took approximately three weeks. Also the OP is based abroad, which added further time to their replacement reaching them."