Codecademy export

script.py

class Patient:
  def __init__(self, name, age, sex, bmi, num_of_children, smoker):
    self.name = name
    self.age = age
    # add more parameters here
    self.sex = sex
    self.bmi = bmi
    self.num_of_children = num_of_children
    self.smoker = smoker
  def estimated_insurance_cost(self):
    estimated_cost = 250*self.age - 128*self.sex + 370*self.bmi + 425*self.num_of_children + 24000*self.smoker - 12500
    print("{}’s estimated insurance costs is {} dollars.".format(self.name, estimated_cost))

patient1 = Patient("John Doe", 25, 1, 22.2, 0, 0)
print(patient1.estimated_insurance_cost())

Run

I think you should call the estimated_insurance_cost method with a print function because when you return the total estimated cost, you use print.
use the instance of the class variable for Patient
patient1.estimated_insurance_cost()