NGINX validation error?

Question

Nginx

Hello!
When trying to start Nginx on port 80, an error pops up:

[email protected]:/# sudo nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: [emerg] bind() to 0.0.0.0:80 failed (13: Permission denied)
nginx: configuration file /etc/nginx/nginx.conf test failed
[email protected]:/#

At the same time, if you put nginx on a non-standard port, it works, but Let's Encrypt does not want to confirm the domain! How to run nginx on port 80 or how to check a domain in Let's Encrypt on a non-standard port?!
Tell me please!

Answer 1

apparently something else occupied port 80.
Look in the output of the
netstat -pna|grep 80 command, what hangs on this port

Answer 2

443 port ssl, and there are no psychics here

Answer 3

Ports up to 1023 are allowed only for root. What user are you running under?
Well, as already said - someone else could capture the port earlier.
"Permission denied" seems to hint at the first point.

Answer 4

Strange, I just stop nginx, start certbot and it confirms everything itself, then service nginx start and everything is fine. You can also try