Multiply quantity selector by 2 or 4

For my website I have about 20 product that are sold in packages of 2 or 4. I would very much like my customers to see the price as it is for 1 piece but when clicking on the prodcut page in the UX be forced by automatically buy 2 or 4.

I want my own layout and css to remain the exact same as it is. I downloaded an app that should do this, it however added a whole new button and quantitiy selector that really does not fit and looks strange.

Is there an app that can help me?

Hello @L1B3A , For to do this quantity increases with 2 or 4 multiplier you can set your input values like min, max, quantity_rule of the products in your code.
you can set quantity_rule of the min for minimum quantity equals to 2 or 4, can set quantity max rule with your choice if you want to set 20 then quantity_rule of the max for maximum quantity equals to 20. For 2 or 4 multiplier set of products please set a steps attribute of the input equals to 2, this can add 2…2 products with 2 steps addition for quantity_rule.increment.
Please the screenshot below.

You can set the values of quantity_rule.min, quantity_rule.max, quantity_rule.increment by your choices, Please refer this quantity-pricing document.

My Theme doesn’t quite have that page. I’ve already tried to do this by setting an if statement, that if it has a metafield with a specific number, then set the increment and decrement to that number. However with my theme (prestige) I don’t see where I should put this. I’m getting major errors everywhere.