create aspx or php API integration server to server Mysql / SOAP

I have a bills payment system, and the service provider has provided me an existing website link for this and they are using ASPX but my wordpress is hosted using Linux, can i use my API tech details on my existing host i want it to be set up in my own domain so what i need is a server to server setup for API. I want to modify the existing website for us with additional features: I can send you the site link with username and password to check the existing site just private message me. Features i need is: Bills payment portal Admin side: a. Branch Management 1. Create branches 2. Create users 3. Create balance / Limit b. Admin Tool Box 1. Admin report detail 2. Totals per branch 3. Totals per users 4. Balance inquiry c. Create custom payment system 1. Create bills to accept 2. Create fees for users 3. Create commissions for admin 4. Create commission for users 4. Print payments history per bill or all 5. Totals new payment system d. Deposit information 1. get notification when a branch or user uploads a deposit slip: 2. option to fund their account once deposit is verified * for user side when they click on deposit slip upload fill up the following details Bank Name: Account Name: Account Number: Deposited by: wire transfer or branch deposit Branch deposited to: Account type Current or Saving User side: 1. E-Load 2. Prepaid Cards 3. Electronic Cash 4. Bills Payment 5. Customs Bills Payment 6. Reports 7. Online Help 8. Control Panel 9. Balance Inquiry 10. Upload deposit slip 11. add balance by paypal * for the custom payment system, i want to be able to upload a logo, create fees EX: Php 5 pesos per transaction, with the following details: Account Name: Account Number: Reference Number: (optional) Total amount to be paid: * There should also be and export options for the total amount paid with complete details * There should be a print options for complete details and amount paid * The custom bills payment balance and transactions are not part of the system, this should have its own transactions search, total amount paid and total amount of fees * There should be a balance setup per branch so that they will not be able to transact once their balance is depleted. * I want balance email notification once the balance is already low in funds for admin and users * There should be a balance inquiry with total amount of our commissions for admin.