How should my smart dimmer be connected?
I found the instruction sheet here.

From that:

We can’t tell which your hot feed is:  blue or yellow.  You need to determine that, one way is a meter, another way is a non-contact voltage detector with the old switch turned off.

On the new switch:
BLK is where the hot wire goes.  (My guess is the blues)

RD is where the load goes, that will be other wire on the old switch.(my guess is yellow)

WH is neutral.  You’ll need a 6” white wire scrap for this. Attach that scrap  here and add the other end to the wire-nutted bundle of neutrals in the back of the box

You won’t use YL/RD in this instance. Leave the label covering the screw per the instructions.  (It would only be used when multiple switches control the same light.)

The difference is your old switch didn’t need neutral.  Smart switches always do, and fortunately neutral is available in the box (that is not always the case.)

What is in that tape? It shouldn’t be there. Splices require wire nuts instead.