I want to publish the private key of the SSL certificate from the test domain for test purposes. Is this a good idea?

Question

Digital certificates

Now, for local testing of a web application under https, I use an SSL certificate from a domain that I own. I send a request to 127.0.0.1 through hosts. I want to use a similar technique in my open-source project. To do this, I want to buy a separate domain, get a free SSL certificate from Let's Encrypt for it, and place the entire certificate (along with the private key) publicly.

Then anyone can install it locally and immediately get green https in any browser, without suffering from a self-signed certificate. For example, it will be the https://my-test-https.com domain , I will publish the key directly on it in various formats, and I will take the hosting from GitHub Pages.

Is this a good idea?
Doesn't this violate any rules of the issuer of the certificate?

Answer 1

I did not understand why all this. Lets gives a certificate for 90 days. The most ordinary, without DV/EV. Any self-made certificate is exactly the same for testing - there is no need to go anywhere, download anything, and in any case, you will need minimal knowledge about certificates.

Answer 2

green lets do not exist)) only for money
big such money

Answer 3

Also offer your options for a domain name. The certificate will be used not only on the local machine, but also for testing web applications over the local network, so a universal option is needed.
I will publish the created site here in the form of an answer.