No you cant, there is no feature to be able to put Tritium from the FC's stock to the fuel reserve remotelyNot entirely true. Tritium can be carried on the carrier as stock which can be transferred remotely to the store at need.
However, when that stock is depleted then you are forced to find some way to refill the carrier. This can be done by getting other commanders to donate.
More likely you will have to fill it yourself.
You are correct. I had failed to test this properly. I always had reliable passengers to buy tritium on the cheap and donate it to the store.No you cant, there is no feature to be able to put Tritium from the FC's stock to the fuel reserve remotely