To be honest you're probably better off using the official "Erwin" SEAT online service and maintenance documentation that dealers use, I don't think the Haynes
guide for the 2017+
Ibiza is meant to be very good.
With Erwin you pay for access for a particular time period, I just bought access for a day, then saved as PDF files all the sections that I wanted (mostly for general servicing), for later printing out as needed. Think it cost about 30 euros.