For certain SDKs you have to manually enable capturing of IP addresses. Here are some examples:
C#
Sentry.ConfigureScope(s => s.User.IpAddress = "{{auto}}");
or:
Sentry.Init(o => o.BeforeSend = e => { e.User.IpAddress = "{{auto}}";
return e; });
Java
Sentry.getContext().setUser(
new UserBuilder().setIpAddress({{auto}}).build()
);
Native
sentry[user][ip_address]={{auto}}