Can I check in any number of Check-in Baggage within the weight of Check-In Baggage Fee I purchased?

You will be asked to pay an checked baggage fee for each piece.
For example, if you purchase the Check-In Baggage Fee (one, up to 23kg) and the Check-In Baggage Fee (one, up to 32kg), you can check in up to 1 piece of baggage up to 23 kg and 1 piece of baggage up to 32 kg, for a total of 2 pieces.

Please check below for details regarding Baggage.
https://www.zipair.net/en/service/baggage