Unable to use if else statement in Mobile application testing

My scenario is, A screen appears intermittently and I want to tap close button in screen, if it appears or tap on another button when it doesn’t. I tried many statements given for webUI. But nothing worked.

if (Mobile.verifyElementExist(findTestObject(‘Live Mode/Secure Message screen X_Btn’), true)) {
Mobile.tap(findTestObject(‘Live Mode/Secure Message screen X_Btn’))
} else {
‘Tapping on More Menu opens Left Menu list.’
Mobile.tap(findTestObject(‘Live Mode/More Menu_Btn’), 0)

Katalon image:

I do not understand this sentence. It does not make sense to me.
Could you restate it?

Mobile.verifyElementExist keyword takes an int value as the 2nd argument.

But you wrote:

Mobile.verifyElementExist(findTestObject(‘Live Mode/Secure Message screen X_Btn’),

This will never work.