SendKeys for javascript, only last character shows up in textfield


I am using javascript(mocha and chai), appium and youi engine. Here is the link:

There is a section that I want to test which is filling in a textbox(automation test).

According to the link send Keys is a method I should use when filling in the blank. I tried it and it kind of work, basically if I have an email textbox and i wrote…addValues(the equivalent of send keys but for javascript). Only the last character will be populated.

For example if I use addValues("[email protected]") only “m” would show up.

The only way for it to work is if I made it in a for loop. But I do not understand, it should work without a for loop.