Yes, I entered it in the promotional code area which is directly after booking, not during payment like for the other vouchers. When you enter it at the end during payment it gives you the 125 prefix, which I did try but it didn’t work. When I entered it in the correct area, it just made a blue circle like it was busy getting the voucher to work, but never completed it. I left it running for 10 minutes and it never went through. I’ve tried it many times again and again and same result. I’ve seen other people in this forum talking about the same thing. I even did a screen recording of me doing it which lasts 11 minutes.

Screenshot from my screen recording