JIRA Service Desk "Then Webhook" could not validate some character

Steps to Reproduce:

1. Navigate to a JIRA Service Desk Project
2. Move to the Project Administartion page and click "Automation".
3. Create a Custom Rule and set any "IF" condition
4. Choose Webhook for the "Then" condition.
5. Put a Random URL like:

   http://localhost:8080/jira/{}

6. Click Confirm

Expected Result:

• The URL will be accepted

Actualy Result:

• "Invalid URL provided" error message will be shown.

Notes:

• Tried with ?,$,& it work so far
• Using JIRA standard Webhook is accepted as well.