hey Mikrotik support guys >> 
i’ve been on UM since 7 months or may be a little bit more it is quite enough system easy to use but i think it lack to one feature which is in the title above recharging by pin code option even if i can pay to get this feature on MIKROTIK UM not on other radius systems .
i think it will make UM integrated with itself good Luck and thanks for this system
Best Regards