use redirect
visit https://a.com redirect to https://www.a.com jiu
access ppp.a.com redirect to https://ppp.a.com

I am not very clear about the situation of the public network. I will only mention a few points for those I have come into contact with:

A "Your connection is not private" prompt appears for
1. . You should first search for the certificate issuing authority used to see if it is still trusted by Chrome. This prompt will also appear if the organization is cleared from the trusted list by Google
When
2. jumps from a first-level domain name to a second-level domain name with the www prefix, I generally like to directly add an CNAME record to the domain name service provider (Aliyun's Wanwang), that is, resolve xxx.com to an address such as www.xxx.com , and then resolve www.xxx.com to the corresponding IPv4 address (which can be the corresponding host address or load balancer). But this is the setting of Wanwang. I haven't used anything like Godaddy/ Dog Dad. I don't know if it's the same
.
3. you can also set 301 rel= 302 jump in the previous Nginx configuration. Here you can directly refer to nginxconfig.io . In addition, you can also use 301 li 302 to jump to https (of course, you can also use 497)
.