With WooCommerce 5.5 and above PayPal Standard is not available anymore.
WooCommerce suggests now the plugin WooCommerce Payl Payments for activating PayPal.
Unfortunately, WooCommerce PayPal Payments is a disaster, full of bugs.
You can have an idea of the quality of the plugin by having a look at the reviews at https://wordpress.org/plugins/woocommerce-paypal-payments/
Is it still possible to activate PayPal Standard?
Yes, it is, and the solution is dramatically easy. You need nothing else than adding this single line of code to the functions.php of your child theme or to a functional plugin:
add_filter( 'woocommerce_should_load_paypal_standard','__return_true',9999 );
That’s it.
Yes, one single line of code, nothing else. If you don’t believe it, try it yourself.