How can we modify a variable via chart?

[l'andorrà]

I created a small project that is designed to draw a button that once clicked one will open an 'edit field' object on chart that will show the current variable used to select lot size:

https://fxdreema.com/shared/n7KdIRkpc

Everuthing works fine except I cannot edit the lot size value. No matter what lotsize I type in, the variable value is not modified. I'm sure I'm missing something but I don't know what. Could someone please help?

[AlphaOmega]

@l-andorrà brother.. I do not use mt4 but the last time roar explained I have to change the lot-size here: Where do you change it?

[l'andorrà]

@alphaomega This is certainly a way to change a variable's value, but you cannot use as I need. I need to do it manually on the chart.