Maybe can attach a sample app or screenshot to help other contributors understand your issue?

done

Make your subform "item" field a Text Area element type. In the example below, the Name field is a text area in the subform for the advance grid.

i not using advance grid, im using custom grid

my properties is like this 

Beside that i dont have and advance grid

Unfortunately Grid or what you call Custom Grid, does not cater to multiline text. I recommend you to try Advance Grid.

how can i use the advance grid, why i dont have the option?

is it only enterprise mode?

But at my another app i use custom grid can auto multiline

Yes, I Googled and found this website at https://www.joget.org/product/plugin-comparison/ for a comparison of the Joget enterprise and community edition.

so the multiline cant be solve, i think my another app i use grid only it will auto multiline for me..But the other app cannot ald