How to connect the rss channel of a blog to subscribe.ru to send out publications?

Question

Blogs

Good afternoon, colleagues.
I set up the publication of blog posts in social networks and services. I came across an interesting mailing service subscribe.ru. There you can add your own rss channel. I found the manuals on the Internet, but they are apparently outdated already, the service has apparently changed a lot during this time. I will be grateful for sensible advice and manuals. Has anyone worked with this service?