Wrapping is done by sending an asset to the custodian's deposit address and by submitting a wrapping request.
Custodians take fees over the wrapping operation. The exact fee percentage is determined by an off-chain agreement with the custodian.
The amount of an asset that is expected to be wrapped after sending
X to the custodian deposit address is
(X * (100 - fee))/100
fee is percent unit. E.g., 0.2% is denoted by
fee = 0.2.
The user should send
X that corresponds to the amount of the asset that will be wrapped.
After sending an asset to the custodian deposit address the user can submit an on-chain wrapping request.
The mint is completed after the custodian approves the request, and the wrapped asset tokens are sent to the user's address on the respective chain.