MSI GT 1030

https://www.dell.com/en-us/work/shop/msi-gt-1030-2g-lp-oc-graphic-card-2-gb-gddr5-pcie-30-x16-low-profile-hdmi-displayport/apd/aa362018/graphic-video-cards

https://www.youtube.com/watch?v=2y32mBdZHJY

Hate to correct you but the MSI GT1030 graphics card with heatsink but no fan does NOT fit inside the Dell Optiplex 3060. There is simply insufficient space between the PCI Express slot and the PSU to install it as the heatsink is simply too large.

You can only install a Low Profile card which only occupies one slot, due the bad design of this motherboard.

Some graphics you can install,, from lower to higher power are:

1. GT 1030 (30w TDP)

2. Quadro T400 (30w TDP)

3. Quadro T600 (40w TDP)

4. RX 6400 (54w TDP)

There're more options such R5 430, RX 640, GT 730, etc  but these ones are very old and ithere're too weak nowadays.