First and most importantly: Are you running a compatible cassette on the trainer? the Kickr comes with an 11-speed and that won't work with an 8-speed bike because the cog spacing is different, plus 8-speed chains are wider than modern 11/12-speed ones).
(Thanks Chris for pointing that obvious one out in the comments)
If the cassette is compatible, I think this is related to rear derailleur indexing, this is done via the barrel adjuster on the cable's end on RD, the screws are for limits, i.e. how far in and out the chain is allowed to move out at the position of the smallest and largest cog but that doesn't matter in the middle of the cassette.
There are plenty of threads related to this topic, for example Adjust a Shimano 105 9x rear derailleur
Or simply check YouTube's most prominent video on this topic:
Coming from a bike that probably worked just fine with its original wheel in, I would focus on indexing only, a slight quarter turn at a time, reassess and repeat as needed. I use the Kickr app, put some moderate resistance (80-100W) on and then try to pedal and shift through the gears.
I don't know the specs of the bike for sure but if your Scultura 100 features 8-speed Claris, you have to fit spacers (the 1,85 mm spacer usually provided with the Kicker) before adding the cassette.
As Chris has pointed out in the comments, this as all assuming you have a matching cassette installed. As far as I know, the Kickr comes with an 11-speed cassette included and that definitely won't fit an 8-speed bike because the cog spacing is different.
Even if that is the case and properly installed, there is still a slight chance that the indexing on your road bike doesn't match the trainer exactly and it needs slight adjustments (keep that in mind when switching back and forth between indoor and outdoor riding).