SAT Subject Tests and AP Scores

Hi! So I recently took 2 SAT Subject tests, but I don’t think I did too well. If I don’t put that I took the subject test on my application (specifically UC application), can I still submit scores even if I did well? And if I do put that I took it and my scores are way too awful to send in, am I required to send them?

Also, I noticed that college board doesn’t let you pick and choose which AP scores to send in. If I did fail an AP exam, should I self-report it on my application as well or should I just let them see them see the score report?

Thanks!

SAT 2 subject tests are not required by the UC’s, only recommended so you do not have to send them in.
You can self report any AP scores of 3 or above. You send an official score report only to the school where you enroll so do not send them now.

But on the UC Application it lets you put if you took a subject test or not. If I do put that I took it and it turns out to be really bad, is it okay if I don’t send a score report?