How to translate WP Easy Paypal Payment Accept plugin
https://wordpress.org/plugins/wordpress-easy-paypal-payment-or-donation-accept-plugin/
To translate the Field Label "Email Address" and the "Pay Now" button, add the payment form in a page using the shortcode.
See documentation of the plugin shortcodes: https://www.tipsandtricks-hq.com/wordpress-easy-paypal-payment-or-donation-accept-plugin-120 > Shortcode Parameters
[wp_paypal_payment_box email="" options=":|:|:" currency="EUR" other_amount_label="Amount" other_amount=true country_code="US" reference="Email Address" reference_placeholder="Your email address"]
Then in your page translation, translate the shortcode and change the Country Code.
Example Dutch:
[wp_paypal_payment_box email="" options=":|:|:" currency="EUR" other_amount_label="Bedrag" other_amount=true country_code="NL" reference="E-mailadres" reference_placeholder="Je e-mailadres"]