Anyone knows how to sell temasek retail bond t231025 and astrea retail bond b290620?

I would like to redeem the mentioned retail bonds . I understand from the faq that they are "tradeble on the market like a stock". However i cant seem to find an avenue to redeem them earlier than maturity date. tried using fsmone but cant seem to do it though. Anyone knows how to redeem them, would like to divert to other investment products since its price increased and upon selling its more than what is promised of the total interest on it. Thanks