Do you want to use a third-party page builder like Thrive, Beaver, Visual Composer, Oxygen etc. to create your checkout page?
You can create custom checkout pages using any of your favorite page builders.
Under the "Custom tab", there are a bunch of pre-made checkout form templates that have unique shortcodes.
You can embed the form on a sales page or landing page using the shortcodes.
All of these templates solve different purposes.In addition, they are classified into 1-step 2-step, and 3-step formats so that you can choose the one that suits your needs.
The templates are fully customizable. So you can one-click import them and customize them using Customizer.
Follow this process-
Step 1 #Select a template
Select a template, for exmple (1st "Checkout form" template) and click on Import.
Step 2 #Copy the Shortcode on clipboard
Get the Shortcode [wfacp_forms] form from here and copy to your clipboard
Step 3 #Switch to WordPress Editor
Click on "Switch to WordPress Editor" link here
Step 4 # Click on Edit with Oxygen Button (for Example here if Oxygen page builder you have)
Step 5 #Paste the shortcode to your Custom Page within the page builder
Paste the shortcode here in page builder [wfacp_forms] and create your custom checkout design around this.

You can preview your checkout page made via Oxygen, Click here to see it on browser

Note - Using this process, you can make your checkout page any page builder you have. This was just an example with the Oxygen Page Builder.