Hello Irfan
It is not possible to have both ends of a site to site connection be dynamic. At least one of the ends must be static because if both ends don’t know the IP address of the other, no VPN tunnels could be established.
If you have dynamic IPs on both ends (as would occur if you had ADSL connections on both ends with dynamic IPs), you would have to establish a way to find the IP address of one of the ends. This could theoretically be achieved using services like DynDNS, or NoIP, but ASA does not support these. The best practice is to have at least one end have as static IP.
I hope this has been helpful! Stay safe and healthy!
Laz