Going through divorce process with my wife, she signed the notice and acknowledgment of receipt but she refuse to attend divorce proceedings, arguing that the documents I filled using online divorce service onlinedivorcer.com not legit and don't have a power.Is it possible that court will force me to remain in the marriage if she don't agree on divorce? Is there any issue with documents if I used help from side to fill them?
The first question would be whether those papers are indeed "legit", and we don't do product reviews. Assuming the company didn't mess up and she was legally served, the next question would be whether she responded (in the legal sense) or not. If she failed to respond at all within 21 days (add 9 days if she is out of state), then your next step would be to file default divorce paperwork (presumably that's covered in the service you paid for). If she agreed to the divorce and the courts knows that, then you file some more paperwork and she doesn't have to show up to anything.
If she disagreed, there will be an "answer" and possibly a counterpetition. There is an exchange of paperwork w.r.t. assets, a mandatory mediation stage, more paperwork, disclosures etc. and a pre-trial conference, followed by a trial. If you are at this stage, attendance is mandatory. As long as you have proof of service, nobody requested a postponement, and there is some evidence to support your claim, a default judgment can be issued.
It's not clear what "divorce proceeding" you are referring to that involves her attendance. However, you can file divorce paperwork yourself or using an online service, and using an online service does not render the paperwork illegitimate. It's not guaranteed that the service did what would be necessary for you to get the outcome you desire, but that's beyond the scope of what we can tell you.