Get textbox1 text in datagridview1 column 1 cell value

Get textbox1 text in datagridview1 column 1 cell value
I have a form where on button click datagridview is loading and some columns are having combobox values and in one of the column I need text got filled up from the another textbox1 where I will enter the text before hitting that button.

How can I add the text in specific column from source as textbox1.text ?