Can my employer legally demand from me (who is still on sick leave for burnout) to relocate abroad?

I'm working remotely from abroad for a Dutch organisation. My contract stipulates that I'll have to move to the Netherlands when the conditions related to the pandemic will allow it (which is the case now). In the meantime, I've had burnout and I'm on sick leave for more than 3 months. Because I'm about to reintegrate my work, firstly part-time, and then (if it goes well) full time, my employer is now asking me to move to the Netherlands within 2 months. But is he legally allowed to demand that since I'm still on sick leave until I manage to work again full-time? Thank you for your answer.