How Can I Show Exception Message in Custom Error Page in WebForms?

Question

I have written a code in webforms to redirect to the custom error page in web.config file.

 <customErrors mode="On" defaultRedirect="~/ErrorPages/Oops.aspx">
      <error statusCode="500" redirect="~/ErrorPages/StatusCode500.aspx" />
    </customErrors>

And I have written a code which gives me database error.

and the code for StatusCode500 is:

 <div class="d-flex justify-content-center">
            <h1 style="color: #00AEC0">Oops..Could not connect to Database. </h1>
        </div>
          <div class="d-flex justify-content-center">
            <h4 style="color: #00AEC0">Please contact your Network Administrator</h4>
        </div>

It works absolutely fine, but now what I need is I need to pass the exceptional message (Divided by zero error in this case) to the StatusCode500 page just below Please contact you network administrator . How can I pass that exceptional message or Error Id?