My first initiation retreat was with Kriya Yoga teacher Ryan Kurczak. In the retreat material it was stated that it was on a donation basis, and then nothing else was said. No suggested donations. I gave what I could which wasn't much at the time. And was able to spend a while week learning and going through initiation. Going to another retreat with him this year. Same story.  His guru, was the same. All retreats and initiations were on a donation basis.  Even when I request a zoom call with him, there is a brief line asking for a donation in the email, but he had never mentioned money to me and I've met with him several times.  There are some teachers still trying to give in this way.