I have Delta Dental and they do not cover any 'mail order' aligners.
I just started this journey and I pray I made the right choice because my ssi ck. doesn't go far. I have Delta Dental and they do help with aligners up to your maximum orthodontic coverage however you have to have all this done by a dentist or they will pay $0 I pd $1400 for smile love aligners. (Invisiligners are atlest $6k/smile direct $1800) I'm not sure how smile direct club works as they do have local shops all over.
They can help file claims but only if you have orthodontic insurance, it will not be covered under most regular dentistry plans due to cosmetic, only changes front and lower 6 teeth and does not correct cross bite issues in the back.