There are machines on the platforms that 'sell' the IC Direct supplements but AFAIK, they only work with OV-Chipkaarts (they're like the regular tap in/out posts for OV-Chipkaarts, but red rather than yellow - they presumably work by deducting the cost of the supplement from the balance of your OV-Chipkaart). So, this wouldn't help the OP if they're travelling on a paper ticket. However, if the OP is going to do much travel on public transport in the Netherlands, then it may be worth getting an OV-Chipkaart anyway, to avoid the hassle (and additional cost) of buying tickets for each journey. The OV-Chipkaarts are available from some NS ticket machines (not all - but there must be at least some at Schiphol that sell them).

I haven't checked whether the NS ticket machines sell the IC Direct supplements.