If you already have a PayPal account, select "PayPal Check out" and log in with your credentials. If you don't have an account yet, select "Subscribe".
If you selected PayPal Check out, you can now log in. To subscribe using a debit or credit card, you need to create a PayPal account. Fill in all the requested fields.
Please note that your phone number needs to be in the international form. Select "Create Account & Pay Now".