Where can I get a Let's Encrypt certificate and key for a hosting provider?

Question

Digital certificates

I asked the host provider a question: is it possible to change the protocol of the site from http to https?
Received an answer: You will need an SSL certificate, we can offer Comodo PositiveSSL for 2100 rubles / year, protection of one domain, including www.
However, I would be fine with a free option like Let's Encrypt. The hosting provider itself, apparently, cannot do it completely on its own, so it writes: If you send a certificate and a Let's Encrypt key, we'll do it.
In the end, how to be? Where to get, what it requires to solve the problem: moving to https

Answer 1

How to Install Free SSL From Let's Encrypt on Shared Hosting
https://www.hostinger.com/tutorials/ssl/how-to-ins...