Iframe
Implementing a payment form will allow users of an external site to make payments through own site. The documentation provides steps for creating a payment form, data processing of payment, and sizing Iframe.
To set the size of the iframe, set the width and height attributes in the HTML code of your iframe:
Here width is set to 360 pixels and height is set to 700 pixels. These values can be customized according to your preferences and the design of the external site.