Purely guesswork on my part, but I have a feeling that your PCIe slot would be good for up to 75W, but you'll also need to consider the PSU in that system before adding to the build.
I have a feeling that anything more than a GTX 1050 Ti will not be a good idea. In addition, if the 1050 Ti has an additional power connector (some do), you'll also need to ensure your PSU has one to suit.
One thing you could do is install Piriform's Speccy, and get a screen shot of your system's motherboard details. It might yield more information.