SSL for sub-domains


I need help ,please suggest what is the way out .

I’ve a domain ( & i would like to create SSL certificate for various sub-domains like and . Now for this to work does i have to create a A record for each of my sub-domain eg: so that i can run certbot commands & Domain validation can happen .
is it possible later on post generating the certificates can i update that “A record” to “C-Name” for pointing it to my Load balancer.Will there be any effect to my SSL certificate ?

I’m not clear on this , please enlighten me.


it won’t have impact.