me123me123

Let me preface this by saying that this is my first post here, and I am pretty new to PCs in general. So I am trying to put a GTX 1650 Super into my old dell inspiron tower from 2009. Online it says that the card draws 100W, but since my PSU is a cheap 400W (https://www.ebay.com/p/660894006) it doesn't come with 6-pin cables. I saw a Linus video where he does something similar to what I'm trying to do (https://www.youtube.com/watch?v=56MgVgnRBSs) with a sata to 6-pin adapter, but I am still not sure how safe it is. If I used a molex to 6-pin adapter like this one (http://www.emartone.com/ebay_images/ebay_product_images/computer_cables/Dual%20Molex%20to%206pin%20PCI%20E%20Power%20Cable.jpg) will I be fine? In the video Linus says that he should be fine because of the low power draw from the card, but I am not entirely sure how it works or why so many people look down on this sort of thing. Also, I could theoretically upgrade my PSU in the future, but I prefer not to spend any extra money on this old PC. Thanks to anyone who can help!