Yep, it doesn't support SLI via SLI bridge, if that's what you mean.

Regardless, SLI is not recommended unless you are doing scientific computing and have a huge budget where you put multiple Quadros together. For gaming, SLI is not supported in all games, and there is almost no graphics card configuration where 2x cheap graka is better than 1x expensive graka (at the same total price). Even in games where it is supported, e.g. 2x GTX 1080 are almost always slower than a single 2080 Ti, at the same price and although the 2080 Ti is nowhere near twice as fast as a 1080. Furthermore, it often happens that games in SLI stutter/jerk, generally do not run as smoothly or even slower than with a single card.

Therefore: Instead of SLI, think about what your budget is and then buy the fastest single graphics card that fits.