RegEx not containing specific numbers group GoLang - regex

Question

I am using GoLang RegEx to find a specific number in a message
Invite code for the server ABC
your code is: 4361858022791184384
I am using this RegEx
([0-9]){19}
I want to delete any message which does not contain any invite code.
So that people can only send invite code to that specific place and specific action can be performed. And useless messages get deleted automatically.
I tried to negate it, but it also ignores other numbers.
I want a regex that captures every message which does not contain exactly 19 digits number.

Answer 1

FindString returns an empty string on failure, and Find returns nil. So
you could test against that:
package main
import "regexp"
const s = `Invite code for the server ABC
your code is: 4361858022791184384`
func main() {
re := regexp.MustCompile(`\d{19}`)
find := re.FindString(s)
if find == "" {
panic(re)
}
println(find)
}
https://golang.org/pkg/regexp#Regexp.Find
https://golang.org/pkg/regexp#Regexp.FindString