Newsletter form - add field firstname?

Hi! is it possible in newsletter add field with "firstname"?

Now we have email, without firstname? can we change that in admin panel? (and we want to send it to sendinblue?)

There is no such option to add the first name in the newsletter from the admin panel.
Backend code modification is required.

Uuu... :( i was thinking i miss this. Thanks for help.

Sorry @Zyje_sobie, little misunderstanding.
You can use customer email tokens here.
For first name - %Customer.FirstName%
last name - %Customer.LastName%
Full name - %Customer.FullName%

Yes, but it's works when Client is registered.

I talk about situation where CLient use "newsletter form" (footer). And there is only email (?)

In that case,  we don't have their names. So, it is not possible to add their names.
But if you want, you can add a common string for them by checking if the customer name is NullOrEmpty.