Any WooCommerce payment gateway will be automatically available for wallet topup.

Okay, the PayPal Payments plugin is new and we believe that the plugin is not fully compatible with WooCommerce but not sure. Could you please try with deactivate our plugin and using the WooCommerce default coupon? As we are using the default WooCommerce negative fee for partial payment.

Also, you can disable partial payment using code

add_filter('woo_wallet_disable_partial_payment', '__return_true');

Please share the full order payload details.

Please use below-attached code into active theme function.php file

add_filter('woo_wallet_withdrawal_bacs_account', 'woo_wallet_withdrawal_bacs_account_callback');
if(!function_exists('woo_wallet_withdrawal_bacs_account_callback')){
    function woo_wallet_withdrawal_bacs_account_callback($bank_account_details){
        $bank_account_details = array(
            array(
                'label' => __('Phone Number', 'woo-wallet-withdrawal'),
                'name' => 'bacs_phone_no'
            ),
            array(
                'label' => __('UPI ID', 'woo-wallet-withdrawal'),
                'name' => 'bacs_upi_id'
            )
        );
        return $bank_account_details;
    }
}

Please let us know which multicurrency plugin for WooCommerce you are using.

Yes, but we have to do some custom code then.

Sorry at this point this is not possible. But users can change the bank account details before sending a withdrawal requests.