The finer details of what people have been asking for with "mono legato" is not readily apparent in the video. The video is going to be using portamento. In order to tell if this is mono legato or not - the player would have to "smear" all notes over a relatively wide range -- hitting as many notes as possible (probably just all white notes) so one could hear if the sample was retriggered with an attack or not. From what's played - the attack could be there and this would not be considered what most are asking for as Mono Legato.

If you want the exact sound as in the video - I would say you wouldn't need "mono legato" as requested previously.

There's not enough shown to tell everything played - including the other hand. Some of this may be velocity triggered and a sampled effect of "legato mono" or triggered by using an A.SW1/2.

Saxophone sounds that utilize the “mono legato” behavior as in the video, typically have either the word “legato” in the Performance Name or they may have the suffix “AF1” or “AF2” (indication the Assignable Function Switches may activate legato).

From the HOME screen
Press [CATEGORY SEARCH]
Set the Bank = Preset
In the box with the magnifying glass type the word: legato
You should now see performances that utilize the legato articulation.