The basic theory here is: Use comments.
Some relevant posts on MSE:
Why is the chat on Meta Stack Overflow not open to new users?
It's the same reason that the other chat sites have a minimum reputation requirement: To prevent new users from using the chat as a replacement for the Q&A site.
Can users with less reputation be allowed to chat?
If you can't ask an intelligent & coherent question on the site, then I'm not really sure we want you participating in chat, either. Comments are great when you need to ask for additional clarification information, but when you get to the point of requiring an extended discussion in the comment section just to make sense of the question, red flags should start going up.
And it's not that hard to gain chat privileges—only a nominal 20 reputation points are required. In other words, you need two upvotes on (an) answer(s). That seems like a sufficiently minimal bar to me. If you don't have any insights to share that are worth a measly two upvotes somewhere on the [network], then we can probably afford to stand the chance that you'll take your online presence elsewhere.
Others have requested this. You'd likely want to upvote:
Invite low rep users to participate in chat
What we can do now:
If you feel there's a need for a low-rep user to be invited into chat, please flag the question for moderator attention. Diamond Mods can invite users into chat.