my friend i didnt understand wht do you mean by key and field_key :/

key and field_key are the names under you will pass the values of the form fields in the context, using those names from the context you will retrieve the values latter on the button method or for what you need. Note that key and field_key could be any other names

Also you need to know that before your button method is called... the form get saved

can i pass the values without saving??!!

how can i add the button print in the popup because i have a report to join ??

Of course, but you will not pass values without saving, the form will be saved automatically, but if not get saved it will still build the context using the values and field values that you define

Too many questions in the comments my friend, it's better to build a good question explaining everything you need, so you get a more direct answer

You could define one button for the form 1 to open the popup and another button in the form 2 of the popup to use the context values and return a report dict action

friend here is the link of my new answer if you want to help me please: https://www.odoo.com/fr_FR/forum/help-1/question/how-to-work-with-pop-ups-in-open-erp-94092

It will be better if you provide an example of what you are trying to the after test everything that I write here and on the other question, so this questions get a proper answer, you could also edit the original question with the better description and examples

i have put the function in the other question would you help plz

allooooooooo