Will I have to pay back the tax credit through ACA health plan?

I just came out of a meeting to get myself the ACA silver health plan after getting kicked off medicaid because my income exceeded the threshold in my state after I got a raise at work. I thought I understood everything during the meeting, but now I’m freaking out a bit. I was under the impression the tax credit that covers a certain amount of the monthly payment was paid for by the state or something based on my income – but now I’m thinking about it and trying to research, and it seems it comes out of your income tax each year (but in advance)? Is that correct?

If so – here’s my dilemma. I don’t usually get much back at all each year, if any. I don’t know why, and I don’t ever owe, but I normally get back maybe 15 from state and 100 or less federal (or vice versa? I don’t remember). So if $344 (that’s what, based on my income, it is covering each month) is approved to cover my monthly insurance plan, where does this money come from? Am I going to have to owe hundreds or thousands of dollars each year during tax season now?

I wish I understood better when I was in my appointment, but honestly this stuff is very hard for me to understand. So I’m already signed up now.

Additional info if needed – I file individually, 31 age, claim 0 dependents (? I hope i’m wording that right), I work part time, gross salary is around 23k yearly

What should I expect for tax season, and should I change anything?