modify an existing plugin for adding functions

i want to modify the attached plugin (the attached plugin is based on gravityforms) in such a way that the codes that i insert should be linked or assigned to woocommerce products, check the plugin demo here frontend: [login to view URL] backend: [login to view URL] user: demo pass:demo after genuine code submission the customer should see a small thumbnail image and product title like this: thank you for registering your product or whatever i could changed later. [thumbnail image] Product: XYZ Woocommerce Product ""in the backed of used product section i should see the related product and the date when they registered."" (right now this function is not in attached plugin invitation-code-plugin) attached plugin details: You send out personal invitations via an OFFLINE source to register on your website, but only want users you sent a code to to register You have multiple invitation codes for different online sources and want to track which source brings the most registrations by the code you gave out You sell software and only want those who purchased to register on your site for support/updates You are doing a soft-launch and only want to invite a few people to register on your site Features include: Register by Invitation Code Only Form Submission by Code Verification Generate Codes on a Front-end Page or Gravity Forms Confirmation Message via Shortcode Show “Invitation Code Name” on a confirmaiton page via Shortcode (useful if the names of your Invitation Codes are names of People or Companies) Example: Your confirmation page would say this “Thanks [invitation_code_name]!” on the backend page editor and say “Thanks Mary Smith!” on the front-end for visitors to see Upload Codes via CSV View Codes Used by Registered User View Number of Times a Code is Used Set Number of Times a Code can be Used Add invite code field right from the Gravity Forms Form Builder Rename Invitation Code label to something else like “License Verification”, “Special Offer Code”, etc… Set a custom code error/validation message