What I would like to ask is whether this product exists in the banking system of your country and why, in your opinion, are there central banks that do not allow it? Also, is this possible on online virtual banks?
My personal expectation is that this will be possible with some small local banks or state postal institutions. I also expect that this is not allowed in other laws because I have not heard of it much.
Yes, AFAIK it is called time deposit in our country. All banks supported it, though they have the same terms when you have decided to lock your funds for a certain period of time, the interest rate differs depending on the bank.
If I remember correctly, my parents did this when I was young, the money they locked in was set to be received once I turned 18 years of age and was supposed to be used for my studies.
I'm not sure nowadays if they also offer a time deposit using virtual banks but as far as I know, the record of the deposited money that is put on the time deposit is being transferred to a bank passbook which can only be updated if you go directly to the bank.