[docs] update Register a tax certificate (#20585)

* update tax certificate upload instructions

* updated url

* changes as per reviewdog

* updates acc to reviewer

Author: kanwal-kaur

content/billing/tax-certificate.md

@@ -28,14 +28,15 @@ Palo Alto, CA 94306
 
 ## Register a tax certificate
 
-1. [Submit a Docker Support ticket](https://hub.docker.com/support/contact) to initiate the process to register a tax certificate.
-2. Enter the required information. Select **Billing** from the **Topic** drop-down.
+1. [Submit a Docker Support ticket](https://hub.docker.com/support/contact?topic=Billing&subtopic=Tax%20information) to initiate the process to register a tax certificate.
+2. Enter the required information.
 3. In the **Additional Information** field, list the Docker ID/namespace(s) of the accounts that you want to apply the tax exemption certificate to.  
 
    > **Tip**
    >
    > You can list multiple namespaces that share the same tax exemption certificate, if applicable.
    { .tip }
-4. Select **Submit**.
+4. Add the tax certificate from your system by dragging and dropping them onto the file area, or select the **Browse Files** button to open a file dialog.
+5. Select **Submit**.
 
-Docker's Support team will reach out for you to submit your certificate once a ticket is open. You'll receive a confirmation from Docker once your tax exemption status has processed and is applied to your account.
+Docker's support team will reach out to you if any additional information is required. You'll receive an e-mail confirmation from Docker once your tax exemption status is applied to your account.