adding code to the form

I’d like to add some code to the standard form. I see where I can add fields but I do not understand how it works. For example I need to add the following:
<input type=”hidden” id=”00N40000001XwPv” name=”00N40000001XwPv” value=”The Palms”/>
<input type=”hidden” id=”00N40000001WyzU” name=”00N40000001WyzU” value=\’93Website\’94/>
<input type=”hidden” id=”00N400000028xJB” name=”00N400000028xJB” value=\’93Website\’94/>
<input type=”hidden” id=”00N4000000279i2″ name=”00N4000000279i2″ value=”TODAY” />
<input type=”hidden” id=”00N4000000279cJ” name=”00N4000000279cJ” value=”3%” />
<input type=”hidden” id=”00N4000000278pX” name=”00N4000000278pX” value=”2. Info Response” />

How can I use the add field to get this done?

https://wordpress.org/plugins/salesforce-wordpress-to-lead/