Hello,
After going your job description, I am an expert Web developer. I will surely add payment gateway in your website like paypal, stripe etc. I have more than 6 year experience in HTML, PHP, Website Design, WordPress and development.
You can be sure of a quality result from our end and a complete solution for Web, please let me know if you have any query related to the above and I'll be glad to answer,
Looking forward to working with you on your task,
Best Regards,
Manish