How to install a self-signed certificate?

Question

linux

Greetings!
I created a self-signed certificate for nginx, configured nginx myself, but I can’t get it to work without questions.
When trying to access the Chrome/Chromium/Vivaldi page, it gives an error:

NET::ERR_CERT_COMMON_NAME_INVALID

Firefox :

The certificate is not trusted because it is self-signed. Error Code: SEC_ERROR_UNKNOWN_ISSUER

Tried to install a certificate on the system:

сp  mycert.crt /usr/local/share/ca-certificates
update-ca-certificates

But Chrome on the side.
Added to the "certificate authorities" of the browser: vivaldi://settings/certificates, still does not want =(
Vivaldi 1.14 browser, Linux Mint (Ubuntu).
Tell me how to add a certificate correctly?

Answer 1

there is also Advanced (I don’t know how in Russian) and a button to go ...

Answer 2

Tried to install a certificate on the system

Installation into the system is an installation into the operating system. It must be installed in the browser
itself . Browsers have their own certificate store. Everyone has their own.

Answer 3

The Vivaldi error indicates that the site name and the name in the certificate are different. FF's error is that it is not trusted. FF has its own storage, it needs to be added to the trusted ones separately.

Answer 4

tell me if you can put the certificate. I could not get. no matter how much I bet, it's still red