How do I get rid of this deep line/wrinkle?

You may have better results from a combination of treatments. Fillers can be used to soften the appearance of deep lines and wrinkles. You can consider adding Morpheus8 as well. These treatments combine RF technology with microneedling to improve overall skin tone and texture. I've included a video I hope you find helpful.

To address deep lines or wrinkles that have persisted despite previous treatments, there are several options you might consider:

Targeted Filler Injections: If the line is particularly deep, injecting filler directly into the line itself may help to smooth it out. This approach can be effective when fillers placed in surrounding areas have not fully addressed the concern.

Combination Treatments: Sometimes, a combination of treatments can yield better results. Consider combining fillers with other modalities such as laser resurfacing, microneedling, or chemical peels. These treatments can help improve skin texture and stimulate collagen production, complementing the effects of fillers.

Botulinum Toxin Injections: If the line is dynamic (caused by muscle movement), Botox or similar neuromodulators might help relax the muscle and reduce the appearance of the wrinkle.

Consultation with a Specialist: Since you've already seen several board-certified injectors, it might be beneficial to consult with a dermatologist or plastic surgeon who specializes in complex cases. They can provide a comprehensive evaluation and tailor a treatment plan specific to your needs.

It's important to have a detailed discussion with your provider about your goals and the potential options, as well as the risks and benefits of each treatment.