Hi @evilmc
Our plugin Custom Payment Gateways for WooCommerce uses default WooCommerce status of Pending Payment. These Pending Payment Orders are part of the “Hold Stock” feature of WooCommerce.
To modify this please go to WooCommerce > Settings > Products > Inventory.
Here you will see an option to modify Hold Stock. You will need to edit this field and update it to 28800 – which corresponds to 20 days.
Here is a screenshot of the same: https://prnt.sc/w3SZnDvMQl4o
Do let me know if you have any other questions.
Best Regards,
Dhruvin Shah