Auto post does not work

Hello! I bought the Redditomatic Plugin. I tried to make a new post to test and also I tried to manually post older posts. But it keeps giving me the same error. I added the error log and the error code as attachment. I am not sure whay it does not work. My host is WPUMDEV and I use CloudFlare Under Attack Mode. When I disable UAM the site becomes terribly slow. Can you help me out? Kiss, Susana