Needs to call webview button by External Button

Hello Guys I dont know how to clarify but… I will try to explain my issue more clearly

Lets take a example this is a Facebook page…
So I will show it on webview

And I marked login
When login clicked it will start signin progress…
So my question is…
I want to call or make click that login button

Using button component.
So that webview will qutomatically start login process

Is it possible ?
Any webview string
Js ?
If yes or you understand question… answer plz