How much a given card can use is variable, so there's no definitive answer. If the card uses a 6 pin connector then it can use up to the 75 extra watts that connector provides, although a 1050 Ti won't use that much in practice.
Perhaps a bit more. Power usage is capped at 75w total. From Tom's review look like almost all the power came through the 6-pin connector and not the PCI slot.
The GTX 1050 Ti models I have seen require 300W or greater power supply. No additional power connector needed and a theoretical 75w is available from the PCI express x16 slot.