Ah, then look up your monitor on
this page, it'll give you the FreeSync range (minimum and maximum), and will indicate if the monitor has LFC. LFC basically makes the lowest number half of what it should be.
For example, if your monitor has a 48-100 FreeSync Range, then it can adjust the refresh rate anywhere from 48 to 100. BUT, if it also has LFC (Low Framerate Compensation), then that first number is halved, so your effective range is 24-100. Thus, it can keep things smooth even if the frames dip below 48 fps.
Since your monitor tops out at 75Hz, thus 75fps is the maximum displayable, then a 5500XT (8GB), 1650 Super, or 1660 non-super would be pretty good choices. The 5500XT 4GB is a little hard to recommend, whereas the 1650 Super handles 4GB a little bit better. The cheapest 8GB 5500XT is at the price of the cheapest 1660, which is a category higher in performance.
A quick look at PCPartPicker shows 1650 Super cards starting at $159.99.
However - it is really almost impossible to recommend the lower end cards, because right now, this 1660 can be had for $199.99 after promo code and mail-in rebate:
https://pcpartpicker.com/product/DJ...-gb-sc-ultra-gaming-video-card-06g-p4-1067-kr
But what makes even THAT a problem is that, for only $3.99 more (after $10 mail-in rebate), so $203.98, this 1660 SUPER can be had:
https://pcpartpicker.com/product/By...r-6-gb-black-gaming-video-card-06g-p4-1061-kr
Here's the list I was looking at, 1650 Super, 5500XT (both 4 and 8GB variants), 1660, and 1660 Super
https://pcpartpicker.com/products/video-card/#c=476,439,450,478&sort=price
The cheapest of the 1650 Super cards might be worth considering if you want to save about $40 bucks, but honestly, bang-for-your-buck, that EVGA 1660 Super for $203.98 is impossible to beat.