We do not yet have this built in as an option, but if you want to change it to auth only it would be pretty easy to do within the plugin code.
For Express Checkout you would open the file at /wp-content/plugins/paypal-for-woocommerce/classes/wc-gateway-paypal-express-angelleye.php
Go to line 1189 and you’ll see the following:
'paymentaction' => 'Sale',
Just change to say Authorization instead of Sale. Then you’ll need to do the exact same thing again on line 1602.
If you’re using Payments Pro (DoDirectPayment) then you would open the file wc-gateway-paypal-pro-angelleye.php and make the same change on line 698.
For PayFlow you would open the file wc-gateway-paypal-pro-payflow-angelleye.php and at line 329 you would adjust the following:
'trxtype' => 'S',
You would just change the S so an A.
In each of those cases, the transaction would hit your PayPal account as an authorization only, and then you would have to capture the funds from directly within the PayPal account when ready to do so.
In the future we will have Auth and Capture included so you can adjust it through the settings, but for now making that adjustment in the code is all I can offer.
Just keep in mind when we run the next update you may have to make the same change again until we get that officially integrated.