Why am I only seeing the Bank Certificate option under "Request Certificates"?

There are two possible reasons: 

You haven't opened a Time Deposit account. 

You just created your Time Deposit (it's currently your Day 1). It will take 6 days for it to be generated.

After 6 days, go to Profile > "Request Certificates." By then, you should be able to see the Time Deposit Certificates option.