We provide payment integration on OJS 3 by using Paypal Plugin or by using the manual payment. By using this service, your journal allow to protect any issues, articles, or galley of any articles, and manage the subscription for your journal by setting up some pricing. We also provide you direct tutorial by phone to make you understand how the payment work flow on OJS 3 system. 
To make sure your privacy on Paypal account protected, we would doing remote connection to your PC that connect to the paypal account so you can monitor what have we done to your Paypal account to make the integration work on OJS 3 system. 

We also provide you with documentation that explain on how to manage or configure this plugin so you can change any time based on the plugin that our team have compiled on the online documentation (exclusive for our customer only). 

*This is not plugin but service for your journal, make sure you can make any phone call to initiate this service.