Can I licenses thru LAS a on-prem Netscaler thru Netscaler Console located on Citrix Cloud?

It depends on the license for the netscaler. Flex, UHMC, and CPL are Console. Fixed are on the box itself.

But the Console can be on Cloud and it's free, right?

"free" it is limited in the data storage. And I have had customers that are using the free console only tenancy and had it removed for no reason. Personally if customers are not cloud, I just run it on prem. And they have a light LAS only version for on-prem if you don't want all the extra add-ons for Console.

I have heard rumors that the built-in agent has been enabled to do LAS properly without a single Agent running, but I do not have a Console Service tenant to test that with. Are you only running NetScaler, or do you have UHMC licenses as well?

I am only running a Netscaler

You will need to obtain a Fixed Bandwidth license. Have you done that?

Yeah, either one or the other, activated directed with LAS and the other we had to go mas_tools thing

Mastools (the local agent) is only going to work with the NetScaler Console Service. If you have licensing for the NetScaler, you should be able to log in to the NetScaler Console Service with an account and view the licenses. Then, you can try to use the built-in agent. My experience has been that at least one Agent needs to be installed (not built-in agent) and acting as the License Service Agent (LSA) but I have been told it is not required now. I can't test it as all my consoles have an LSA. If you would like a walk through of using the Built-in agent, I wrote a blog about it a while ago but it was for flexed. It should be the same process to use it with LAS. https://www.ferroquesystems.com/resource/using-the-built-in-agent-to-license-netscalers-using-flexed-licensing/

This is the problem right now. I had a call with Citrix and I did using just the built in agent on the Netscaler and it activated against LAS.....the issue is that I cannot find any official documentation on this and no procedure on how to do it.....I need to know obviously before the 15