How do I send a hyperlink in mailto in C#

I have a mailto button that copy the actual link of my page.I want that when my users click on the button, it copies them a hyperlink with the link of my page

public void GenerateShareMenu(string copyLink, string emailLink, string msTeamsLink = "")
{
    this.ClientSideEvents.ItemClick = "MenuNoPostBackForGridActionMenu";
    var moreMenu = this.Items.Add();
    moreMenu.Name = "RootMenu";
    moreMenu.TextTemplate = new ITAMMenuTemplate("share", string.Empty, false);

    var copyLinkMenu = moreMenu.Items.Add();
    copyLinkMenu.Text = PSStringUtils.GetString("CommonCopyLink");
    copyLinkMenu.Name = "RootCopyMenu";
    copyLinkMenu.TextTemplate = new ITAMMenuTemplate("link", copyLinkMenu.Text, false);
    copyLinkMenu.NavigateUrl = copyLink;

    //if (!string.IsNullOrEmpty(msTeamsLink))
    //{
    //    var msTeamsMenu = moreMenu.Items.Add();
    //    msTeamsMenu.Text = PSStringUtils.GetString("CommonTeams");
    //    msTeamsMenu.Name = "RootMSTeamsMenu";
    //    msTeamsMenu.TextTemplate = new ITAMMenuTemplate("groups", msTeamsMenu.Text, false);
    //    msTeamsMenu.NavigateUrl = string.Format(CultureInfo.InvariantCulture, @"javascript:$('#{0}').click();", msTeamsLink);
    //}

    if (!string.IsNullOrEmpty(emailLink))
    {
        var sendMailLinkMenu = moreMenu.Items.Add();
        sendMailLinkMenu.Text = PSStringUtils.GetString("Common_SendEmail");
        sendMailLinkMenu.Name = "RootSendMailMenu";
        sendMailLinkMenu.TextTemplate = new ITAMMenuTemplate("forward_to_inbox", sendMailLinkMenu.Text, false);
        string htmlLink = $"<a href='{HttpUtility.HtmlEncode(emailLink)}'>Oui</a>";
        string emailBody = HttpUtility.UrlEncode(htmlLink);
        sendMailLinkMenu.NavigateUrl = $"mailto:?body={emailBody}";
    }
}