If you do not have GCash MasterCard or any other way to verify your PayPal account, but, you have a verified GCash account, then, you can verify your PayPal account and remove its limitation using your GCash AMEX Virtual Pay Credit Card. I just verified my wife's PayPal account this year 2021 and thanks' God, the process was successful. And I will teach you how to do it using my personal experience below.

How to Verify PayPal using GCash American Express Virtual Pay Card

1. Assuming you already registered for a Personal PayPal account, login and inside it, press the Link a credit card link.

2. Now, for the Credit card number, Card type, Expiration date, security code, and Billing address, you need to open your GCash account first and register for an AMEX Virtual Pay Card. You need to do this tutorial first to be able to know what to write in the given form below. After doing the tutorial, type all the needed info and then press the Link Card button.
3. Now, you will be given a Confirm your card link. Just press the link to continue.

4. In Confirming your AMEX card linking to PayPal, you will be charged by $1.95 or more or less P94.00. To be able to verify your PayPal, you will be needing the 4-digit PayPal code. Just press the Get Code button to continue.

5. A message saying: A code is on its way. It should appear on your card statement within 5-7 business day. Just press the Done button to continue.

6. The next step is to request for that PP-code that PayPal sent to your AMEX Virtual Pay Card. Only GCash Support can give you that 4-digit code. So, you need to email GCash to give you that code. In your email, follow the following format. It should include your GCash Full Name, the Date and Time of Transaction (when did you request the PP code), the PayPal Email address, your Mobile Number Linked (or your GCash mobile number), and the First 6 and Last 4 Digits of your AMEX Virtual Pay Card. When done, send the email to supoort@gcash.com.

7. You just need to check your email daily to check whether GCash already sent you the PP-code. If GCash Support is not replying, just follow-up your email. And assuming that GCash support replied with your PP-code, you will then see, similar email below. The email contains your PP-code.

8. Now, login to your PayPal account and press American Express Credit.

9. Now, press the Enter the code to confirm your card link to continue.
10. Find the 4-digit code field and press it.
11. Type the 4-digit PP-code GCash support emailed you and then press the Confirm button.
12. If the 4-digit PP-code is correct, then, you will the the message saying: Your American Express Credit xxxx has been confirmed. Just press the Done button to continue.

13. To surely verify if your PayPal account is verified, just press the following link: https://www.paypal.com/cgi-bin/webscr?cmd=_status. After pressing the link, you will see the following message: Your PayPal account is Verified. You are now Verified PayPal user. 
In addition to increased security, buyers and sellers value your Verified status because it indicates you have passed PayPal security checks. Most importantly, you can now send unlimited payments with your PayPal account.
14. Just press the Return button to go back to your PayPal wallet page. Done!

Note: Based on my personal experience, the GCash Support emailed me the PP-code after 14-days to be exact. Too bad, the time of my request was made when GCash is going to have a long maintenance. Maybe, the verification process would have been more faster if GCash is not having a very long maintenance. But, what matters most now, is that, my wife's PayPal account is already fully-verified using the GCash American Express Virtual Pay Card.