ToSlug, Generate URL slug from a name, title, etc.

_functions-ToSlug.cshtml

@functions {

  // Turn any text or title in to a URL Slug
  // original = https://stackoverflow.com/questions/2920744/url-slugify-algorithm-in-c
  // .ToSlug("My  Title=Heading - &*(-) end-") >> "my-titleheading-end"
  
  public string ToSlug(string phrase)
  {
    byte[] bytes = System.Text.Encoding.GetEncoding("Cyrillic").GetBytes(phrase);
    string str = System.Text.Encoding.ASCII.GetString(bytes);
    str = str.ToLower();
    // invalid chars to hyphens
    str = Regex.Replace(str, @"[^a-z0-9\s-]", "-");
    // convert multiple spaces into one space
    str = Regex.Replace(str, @"\s+", " ").Trim();
    // cut and trim
    str = str.Substring(0, str.Length <= 45 ? str.Length : 45).Trim();
    str = Regex.Replace(str, @"\s", "-"); // hyphens
    // convert multiple hyphens into one hyphen (JRF)
    str = Regex.Replace(str, "-+", "-");
    return str.Trim('-'); // leading/trailing hyphens (JRF)
  }

}
					  

Improvements?

https://github.com/Accuraty/FASS-WP-Authenticator/blob/main/fass-external-login/js/tools.js
^^^
Converting accents seems like a good addition.
Maybe also compare RegExs?