How to enter keystrokes like ENTER,TAB, etc. in firefox browser using protractor framework?

I am trying to enter keystrokes(TAB) in my script.

I have used the following code: browser.actions().sendKeys(protractor.Key.TAB).perform(); This is working in chrome but not working in firefox browser.

browser.actions().sendKeys(protractor.Key.TAB).sendKeys(protractor.Key.ENTER); browser.actions().sendKeys(protractor.Key.TAB).sendKeys(protractor.Key.RETURN); These 2 approaches are not even working in chrome also.

I need to run my script in firefox with entering keystrokes. Please help me...