# Dynamic field by request parameter
### How to Use a URL Query Parameter as a Payment Price
The core idea is to add a hidden form field and leverage Elementor Dynamic tags with Request Parameters to prefill values from the URL. Then, in your payment settings, you can use **shortcodes** to link the form value with your payment process.
### Step-by-Step Instructions:
1. Create a hidden field for the amount or even the price ID for a subscription
2. Given a meaningful field ID and click the dynamic tag icon in the Default Value input box
3. Choose **Site → Request Parameter** from the dynamic tag list and select GET type
4. Copy the generated shortcode, then in the "Actions After Submit" list, add "Credit Card Submission" - this will display the Credit Card Submission tab where all your payment settings are located
5. Find the amount field in the payment settings and paste the shortcode.
### Testing by giving an amount parameter in the URL
Test your setup by adding a `amount` parameter with a value in the URL, such as:
