Apple Music Beats Flex offer by Unidays

I've claimed a student offer for apple music for beats felx from unidays and then I was supposed to receive an email from apple to claim this beats flex offer, but didn't received it yet. Unidays has provided me with their unique student reference code: B+MsmK6RXkOAW5ujADMTNQ== (this is the code which I used while claiming offer from unidays)