How to Select textarea in Selenium?

I've been working on a project and had much success with selecting web elements using .get_attribute('value') and .get_attribute('text').

I am trying to select the text from the web element in the screenshot below, but can't figure out how to select the text.

I've tried the following:

operation_instructions = driver.find_element_by_id('txtOperationDescription').get_attribute('value')
operation_instructions = driver.find_element_by_id('txtOperationDescription').get_attribute('text')

Per comments I tried the following, but they print a blank line:

print(WebDriverWait(driver,10).until(EC.visibility_of_element_located((By.ID,"txtOperationDescription"))).get_attribute('value'))

print(WebDriverWait(driver,10).until(EC.visibility_of_element_located((By.ID,"txtOperationDescription"))).get_attribute('innerHTML'))

Interestingly when I got None when trying the following:

print(WebDriverWait(driver,10).until(EC.visibility_of_element_located((By.ID,"txtOperationDescription"))).get_attribute('text'))

Before posting the question I tried all the different elements I thought might work such as the following:

operation_instructions = driver.find_element_by_id('txtOperationDescription').get_attribute('textarea')

But I don't see how I can select the text in this field.

Can someone help me? Please and thank you!