Couldn't Use SendKeys()

Hello Katalon Team,
Please help me. It is my first time using Katalon. When I run my project, I found this error:
10-01-2019 04:35:32 PM Test Cases/TC02_Login

Elapsed time: 1m - 12.216s

Test Cases/TC02_Login FAILED.
Reason:
java.lang.IllegalArgumentException: name argument cannot be null
at ch.qos.logback.classic.LoggerContext.getLogger(LoggerContext.java:119)
at ch.qos.logback.classic.LoggerContext.getLogger(LoggerContext.java:53)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:270)
at com.kms.katalon.core.logging.KeywordLogger.(KeywordLogger.java:60)
at TC02_Login.run(TC02_Login:26)
at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194)
at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119)
at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:321)
at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:312)
at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:291)
at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:283)
at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:222)
at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:106)
at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:97)
at com.kms.katalon.core.main.TestCaseMain$runTestCase$0.call(Unknown Source)
at TempTestCase1569922527942.run(TempTestCase1569922527942.groovy:22)

I using sendKeys on my project. But, I still found error. So, how make this running works?

Thanks,
Nia

hi,

is this added to your test class

import org.openqa.selenium.Keys as Keys

Is it for web testing? Is same with mobile testing?

but, after add the library, it becomes like this