HTML button to open URL in a new window

I'm populating an email template and I'm having some issues with the button onclick event.

What I am trying to achieve is when clicking on the button it should open a URL in a new window rather than a new tab.

Currently when the email gets sent it is losing the onclick event functionality. Any recommendations on how can I achieve this?

I have also tried creating the button in the html template rather than replacing the tags as code below, but still run into the same issue.

HTML Code:

<p>
        Hi,
    </p>
    <p>
        A [JobType], to start on [JobStartDate]
        <br />
        Click here to view the job: [JobUrl]
    </p>
    <p>
        <b>Job Details:</b>
        <br />
        - Reference: [JobReferenceNumber]
        <br />
        - Checklist: [AnswerEvaluationName]
        <br />
        - Created by: [JobCreator]
        <br />
    </p>
    <p>
        Kind regards<br />
    </p>
    <p class="auto-style6">
        Please do not reply to this system generated email
    </p>
</body>

public void CreateEmailNotificationForNewJob()
{
   // Populate the Email Template
   string EmailRecipientTestingNotes = "";
   string EmailSubject = "";
   string EmailTemplate = EmailSender.LoadEmailTemplate("EmailNewJob.html");
   string EmailTo = "";
   string TestButton = ("<input type=\"button\" onclick=\"window.open('https://www.google.com/','mywin','width=500,height=500');\">");

   EmailSubject = "Job/task ";
   EmailTemplate = EmailTemplate.Replace("[JobReferenceNumber]", "Reference");
   EmailTemplate = EmailTemplate.Replace("[AnswerEvaluationName]", "Daily Update");
   EmailTemplate = EmailTemplate.Replace("[JobStartDate]", "Today");
   EmailTemplate = EmailTemplate.Replace("[JobType]", "1");
   EmailTemplate = EmailTemplate.Replace("[CompanySiteName]", "");
   EmailTemplate = EmailTemplate.Replace("[SiteName]", "");
   EmailTemplate = EmailTemplate.Replace("[JobUrl]", TestButton);

   EmailTo = "test@test.co.za";

   try
   {
      // Send email code
   }
   catch (Exception ex)
   {
      // Add handling
   }
}