URL to which the user’s browser is returned after authorizing permissions. Consider setting this URL to the next page in your flow.
Character length and limitations: no limit.

URL to which the customer is returned if he or she does not log in.

NOTE:
Consider setting this URL to the current page so that the customer is returned to the page he or she was on before being redirected to the login page.
Character length and limitations: no limit

URL to which the user is returned on logout from PayPal.
Character length and limitations: no limit

A list of APIs or API bundles for which access permission is required.

A list of APIs or API bundles for which access permission is required.

A list of APIs or API bundles for which access permission is required.

A list of APIs or API bundles for which access permission is required.

A list of APIs or API bundles for which access permission is optionally requested.

A list of APIs or API bundles for which access permission is optionally requested.

A list of APIs or API bundles for which access permission is optionally requested.

A list of APIs or API bundles for which access permission is optionally requested.

Locale of pages displayed by PayPal during authentication. Character length and limitations: Any two-character country code. The following two-character country codes are supported by PayPal:
AU,
DE,
FR,
IT,
GB,
ES,
US. Any other value will default to US.

Sets the Custom Payment Page Style of PayPal pages associated with this button/link. This value corresponds to the HTML variable page_style for customizing payment pages. The value is the same as the Page Style Name you chose when adding or editing the page style from the Profile subtab of the My Account tab of your PayPal account Character length and limitations: 30 single-byte alphabetic characters.

URL for the image you want to appear at the top left of PayPal pages. The image has a maximum size of 750 pixels wide by 90 pixels high. PayPal recommends that you provide an image that is stored on a secure (https) server. Character length and limit: 127 single-byte alphanumeric characters

Sets the border color around the header on PayPal pages. The border is a 2-pixel perimeter around the header space, which is 750 pixels wide by 90 pixels high. Character length and limitations: Six character HTML hexadecimal color code in ASCII

Sets the background color for the header on PayPal pages. Character length and limitation: Six character HTML hexadecimal color code in ASCII

Sets the background color for the payment page. Character length and limitation: Six character HTML hexadecimal color code in ASCII

The initial flow, which is one of the following values:
login specifies the login flow
signup specifies the sign-up flow
If not specified, the default is login.

Customer’s first name.
Character length and limitations: 25 single-byte characters

Customer’s last name.
Character length and limitations: 25 single-byte characters

Person’s name associated with this address. Character length and limitations: 32 single-byte characters.

First street address. Character length and limitations: 100 single-byte characters.

Second street address. Character length and limitations: 100 single-byte characters.

Name of city. Character length and limitations: 40 single-byte characters.

State or province. Character length and limitations: 40 single-byte characters Required for U.S. addresses only.

U.S. ZIP code or other country-specific postal code. Character length and limitations: 20 single-byte characters.

Country code. Character limit: Two single-byte characters.