First of all, it is a bit reckless to resign from the postgraduate entrance examination. Your present job is good. Most positions in the banking industry actually don't need a master's degree at all. Moreover, talents in non-research positions in finance actually pay more attention to taking 10,000 steps back from experience. Even if you quit your job to take the postgraduate entrance examination, you may not find something better than it is now.
Secondly, the recognition of on-the-job graduate students is hard to say. On the one hand, it is the combination of theory and practice, but on the other hand, the poor employment situation leads more students to choose postgraduate entrance examination, so there are more and more full-time masters. Seriously, if the on-the-job master's degree is inexperienced, it will be a complete failure compared with the full-time master's degree, only slightly better than the foreign master's degree. As far as I know, the HR of CCB does not recognize the on-the-job master's degree, which means that even if you study, you still have a bachelor's degree, because the best job is only a degree certificate. Although you can have a little advantage over undergraduates in promotion and other aspects with that degree certificate, according to the current situation, the recognition of working in a short period of time cannot be compared with full-time work, and you may not be able to work and study at both ends.
If you are going to jump ship to small and medium-sized commercial banks in the future, it is feasible to find a job, but you may be reluctant to leave your present position. Hehe, the treatment in the banking industry depends on your working years in this bank.
So your best plan is to take the certificate.