I’ve found the therapists I’ve seen to be pretty understanding. My current T gave me reduced price sessions initially because we started on Zoom, then she said I could keep paying her the same amount when I saw her in person because I don’t earn much. She normally does charge more for in person appointments though.
Another person I saw (once) was asking £30 a session, and I went for what I thought was an initial consultation and, out of character for me, I didn’t think to check what money was in my wallet before I went. So she let me pay what I had on hand and said don’t worry about the rest I’m not recommending that approach, however! I was hugely embarrassed by it. I’m just trying to say people can be surprisingly flexible, especially when it’s clear you’re not just chancing your arm.