auto update change product value

[spacegremlin]

if correct i use the frozen version, but im not sure because i changed alot hihi.
sorry for al the questions.
i want to auto change when a customer adds a product but then in the checkout she wants 3 pieces.
normally you need to press the refresh button i want to do this automatic.
wich plugin is the best for i think frozen.

(my files go from year 2003 till 2019 because of all the updates)

thank you all for the best solution.

i think after this im almost there with the questions.
i think if this all works i only have an ideal payment question if that would not work hihi.

 

[spacegremlin]

solved.