( This is my preferred solution, not a 100% guarantee of success that works well with your account. )

Step 1: Fake IP to Philippines [ May not need to do this ]
Step 2: Access the following path: https://www.facebook.com/help/contact/649167531904667
Step 3: Select the ad account you want to add payment information to
Step 4: Select "I have a question about payment method" (line 3)
Step 5: Select "Add payment method" (line 1)
Step 6: Select Next "Add payment method now" and fill in card information

Click ADD PAYMENT METHOD NOW then enter your payment card information.