Welcome to the forum.
Now the next thing we need is more information. What are the DTC’s being set? If you don’t have a code reader, any local auto parts store should be able to hook one up, and provide you with the codes. Next is we need to know the symptoms, in detail. Also engine size and mileage is important for us to know when it comes to offering cost advice. Did a shop run a compression test and if so, what are the results? I assume since they told you it’s a compression issue they have done so and should be willing to share this info with you. Anything else you can tell us will help. Does it burn oil, how long have you owned it, is it running good but just won’t pass smog, etc? You provided very few details so we need to start there.