Thanks for the answers.
I checked
https://zwofactory.com/ and, indeed, it is a very easy way to create own intervals. I can link the zwo file to a few roads, in the virtual cycling application I use. I also have a good aproximate of my ftp, after a number of longer and intense virtual rides. But I don't know what percentage of ftp is used in HIIT intervals, nor the duration. For example, I tested some "VO2max" intervals: they use around 120% ftp and they play with number of intervals (6-20), their duration (30-120 seconds) and recovery times.
But, as I understand, "HIIT" intervals are different.
So, what percentages of ftp are used in HIIT? Are there some examples of HIIT intervals, that I can replicate to obtain a "zwo" file and use the power meter and erg mode of the trainer?
Thanks