Michael

Add a paypal button (using shortcode) into your pages/posts 
Edit the wp-content/plugins/wp-paypal-shortcodes/wp-paypal-shortcodes.php for configure the plugin.
<h4>Shortcode</h4>
Add the following shortcodes to integrate PayPal into your pages / posts of wordpress.
<pre><code>[paypalBtn production="true" amount="55" item_name="ProduitB"]
</code></pre>
Insert the button in your pages or posts with this shortcode
<pre><code>[paypalBtn production="true" amount="55" item_name="ProduitB" business="seller@yourSite.com"]
</code></pre>
with the merchant email
<pre><code>[paypalBtn production="true" amount="55" item_name="t-shirt" optiontype0="select" on0="color" os0="red;green;blue;orange;yellow"]
</code></pre>
with option select
<ul>
<li>See the <a href="https://wordpress.org/extend/plugins/wp-paypal-shortcodes/changelog/" rel="ugc">Changelog</a> for what’s new.</li>
</ul>
<h3>Arbitrary section</h3>
Buy a product with a shortcode 
* @param production : choose if you are test phase, or production 
* @param amount : price for your product/service 
* @param currency_code : devise 
* @param shipping : shipping price 
* @param tax : tax price 
* @param return : url for the return (after buy) 
* @param cancel_return : url for the cancel (during the payment phase) 
* @param notify_url : url for the return (after payment validation IPN) 
* @param on0 : nom option 1 
* @param os0 : value option 1 
* @param on1 : nom option 2 
* @param os1 : value option 2 
* @param on2 : nom option 3 
* @param os2 : value option 3 
* @param on3 : nom option 4 
* @param os3 : value option 4 
* @param on4 : nom option 5 
* @param os4 : value option 5 
* @param business : email address of your paypal account 
* @param item_name : name of your product/service 
* @param no_note : autorized to file a note or not 
* @param lc : location 
* @param bn : button type 
* @param custom : custom field
<h4>Usage</h4>
[paypalBtn production=”false” amount=”55″ currency_code=”EUR” shipping=”0.00″ tax=”0.00″ on0=”optionD” os0=”ddd” on1=”optionE” os1=”eee” on2=”optionF” os2=”fff” business=”xxx@xxx.fr” item_name=”ProduitB” no_note=”0″ lc=”FR” bn=”PP-BuyNowBF” custom=”abc”]

WP Paypal Shortcodes

This plugin insert Paypal button (pages, posts).

WP Paypal Shortcodes vs WooCommerce PayPal Payments