if I'm calling a SuiteLet from a UE should I need to provide credentials? I didn't think so but "I'm getting you must be logged in[...]" as an error message.

Can you post your code and Error Screen-shot.

Make sure about the script setting like permission ?

I typically call an external url with no login required if I need to call a suitelet from a UE,

@jmacdonald I had the same issue when I was calling in 2.0. Then I was forced to use external URL.

OK thanks guys, I'm actually in the debugger domain and wondering if that's the issue! I'll report back my findings 😉

Domain differences don't matter if you are using ResolveURL or relative URL.

Are you using 2.0?

yes 2.0. I took the URL being used in the post request and pasted it in to the browser and it worked fine. The only way I have got this to work is set to available without login and that's not ideal.

The way I acheived it with SuiteScript 1.0, I loaded the Suitelet script as a library to user event script and then mocked nlobjRequest and nlobjResponse objects and passed it to the main function of Suitelet like any other javascript function.

@NElliott I had the same issue with 2.0 . I was forced to make it as without login and use the url

Was the suitelet released to all roles