So generally you can read this thread.
https://forums.trainerday.com/t/slope-mode-like-erg-mode-completed/
Here are the steps you need to do
- Take a ramp test. You can do this manually in our app, just adjust the watts to try to hit the target it shows.
- Determine your natural RPM when not thinking about it after you are warmed up for 10 minutes or so. It’s likely different at different intensities but just for a baseline
- Create conversion chart from slope % to watts
- Copy a workout from our DB and add slope %.
See below for more details.
I would determine what is your natural cadence and then create an approximate watts watts conversion for different slopes.
Below is an example
At 60rpm
0% = 50w
1% = 80w
2% = 100w
Then you can find any workout in our database and copy it and add your percentage based on the watts you see, but make sure your FTP is semi-accurate first.
If you are decent in excel you could do this with formulas so the whole conversion process only takes a minute or so. You can copy and paste from our workout editor to excel and back.
That’s it. 
If your RPM is semi-consistent this should be accurate enough for training purposes. Let me know if you have any more questions.