Unable to acess any methods of Appium

I want to perform testing on my android application. For that, I am using Appium with node js. I am not able to use any methods like getText(), clearVlaue(), setText(), sendKeys() etc.
I get the same is not a function error

Following is my desired capabilities:

  platformName: 'Android',
  automationName: 'UiAutomator2',
  deviceName: 'Android',
  app:  'some.apk',
  appWaitActivity: 'com.example.HomeActivity',
  autoGrantPermissions: true,
  autoAcceptAlerts: true

 textView = await client.findElement('xpath', "//*[@text='Screen']");
 value = await textView.getText();