Make Sure Discount Is Enable From Settings of Sales

1.0) All In One Discount Configure As Discount Per Quantity :

Admin can set quantity in settings of website and also set discount according to quantity.

1.1) Quantity and Discount Set In Product :

Quantity and Discount according to quantity is configure inside the Product Template.
If Quantity and discount set in Product Template then Function follow first take discount of product and avoid discount per quantity of setting.

1.2) Disable Discount Per Quantity :

If want to disable discount per quantity feature for specific product just enable config setting in product Disable Discount Per Quantity.

1.3) Cart View with Configuired Settings :

Discount is apply as per quantity and discount value that is configuired. Also product avod from discount where enabled configuration setting Disable Discount Per Quantity.

1.4) Sale Order View As Per Configuration Setting Of Discount Per Quantity :

2.0) All In One Discount Configure As Discount On Total Amount :

Admin can set minimum amount and discount percentage in settings which will automatically apply in order if order or cart total amount is more than minimum amount.

2.1) Cart Page With Configuration Discount On Total Amount :

If total order amountis cross the minimum amount than discount percentage automatically applid to the order.

2.2) Sale Order View As Per Configuration Setting As Discount On Total Amount :

3.0) All In One Discount Configure As Discount Per Product :

3.1) Discount Per Product In Product Template :

Configure discount and message in Product Template.
Message will display at Single Product Page of the website and discount will automatically apply .

3.2) Discount Message In Single Product Page:

3.3) Cart Page With Configuration Discount Per Product :

If discount product added in the cart then discount will automatically apply.

3.4) Sale Order View As Per Configuration Setting As Discount Per Product :

4.0) All In One Discount Configure As Discount Per Category :

4.1) Discont Configuration In Categpry :

Set discount percentage and discount message in Category.

4.2) Discount Message On Category Selection :

4.3) Cart Page With Product of That Category :

Discount will apply only that product where categories of that product contains category with configuired discount configuration.

4.4) Sale Order View As Per Configuration Setting As Discount Per Category :

5.0) All In One Discount Configure As Discount Per Payment Method :

5.1) Discount Configuration In Payment Method :

Admin can set discount percentage, minimum amount to apply discount and maximum amount of dicount with Discount message.
maximum discount amount functionality will automatically apply if discount amount as per percentage cross this limit and discount percentage apply according to maximum discount amount

5.2) Cart Page With Configuration As Discount Per Payment Method :

Discount will not apply in cart but will apply on payment method selection page of the website.

5.3) Payment Page :

Discount will apply in backend sale order.

6.0) All In One Discount Configure As Discount Per Customer :

6.1) Set Discount Percentage In Customer :

6.2) Cart Page of With Configuration As Discount Per Customer :

Discount will only aplly for only if that particuler customer is login otherwise discount will not be apply.