I booked directly with the airline - online doesnt work, as technically it is two fares. But I constructed the itinerary in itasoftware and then called Lufthansa. A bit more expensive, but gotogate never, unless you want to spend months arguing with them via email in case of any change. I had to involve the European Consumer Center to make them pay the “covid” ticket. (BTW this ECC is super useful for all europeans in case of any problem with online purchases).