When ipv6 and v4 are both available, how to use ipv4 but ipv6

SUPPORT QUESTIONS
1

Tailscale version 1.30.2

My network is have ipv4 and ipv6, the ipv6 of my device is public and ipv4 is NAT , but the ipv6 is not fast and not stabilize. So I want use ipv4 not ipv6 to connect each other.