Is it more effective to treat multiple areas at once with Botox from the start?

I am looking into Botox because of the wrinkles between my eyebrows.
I'm a little worried that if I get a consultation, they might recommend treating my forehead or around my eyes as well.

The only thing that bothers me is the space between my eyebrows.
Considering the overall balance of my face, I'm not sure if I should work on other areas as well.

If it is your first time
Is it better to try just one area first and see the results?
I'm wondering if it's natural to do multiple areas at once.