As j-ed wrote, this is actually the wrong forum for these kind of questions.
But because we are willing to help anyway we must ask you to provide more information about your system then.
In order to use TLS/ SSL encryption, an additional program is required: for example openssl (https://www.openssl.org/). And if you want to use TLSv1.3 both applications - the webserver and the encryption program like openssl - need to support TLSv1.3.
Therefore, please check:
if you have openssl or another application for encryption installed
which versions for nginx and “openssl” are installed