unity add not show on mobile why?

unity add seems working in p.c but when i play game on mobile unity add not show in mobile. is there any solution , any help for this ? using unityengine.advertisments; void awake() { advertisment.initialize("101771"); } on level complete i call advertisment by advertisment.show(); when i check on p.c , on level complete unity ad msg show nd print things seems to be working but when i play on mobile then unity add not show on level complete any solution any help? thanx in advance