Replying to a Javascript/jQuery

[snippsat]

I need to see the entire rendered source of the next page

No need to look at whole source.
I pretty much never look at at entire page source,but use dev-tool right click on element to get only chosen Selector.
So tested the start of step-2 will be like this.

continue_next = browser.find_elements_by_css_selector('#StepOneContinueButton')
continue_next[0].click()
# Step-2
time.sleep(3)
phone1 =  browser.find_elements_by_css_selector('#CallerPhoneNumberTextBox')
phone1[0].send_keys("44556677")