Navigate to the WordPress Dashboard > WooCommerce > Settings > Coupon

1. Coupon for first Purchase : Select a coupon for new customers.

It's not working on non-autherized customers.

2. Price Cut From: If you want to discount amount on product's Regular price, then select Regular price. Else select Sale price.

Default value is Regular Price and work only with Product Adjustment Coupon Type's.

3. Multi Coupon: If you want to allow apply multiple coupon's on cart, then select Yes. Else select No.

Default value is Yes

4. Coupon Url slug Name: Give any text on this input to allow apply coupon by URL.

Default value is coupon , that mean url should be

https://example.com/?coupon=coupon_code