Head Blacksmith Opix:
To become an Artisan, you need the appropriate level and token. Your level must be at least 20 to qualify to change profession.
It seems that you have admirably passed the Test of the Artisan, but your level is not high enough. Level 20 or higher is required to change profession. I cannot allow you to change profession if your level is not appropriate, even if you have passed the test. Come back when you raise your level.