According to the dedicated page for X-Men: Dark Phoenix:
The primary facility on Dark Phoenix handled over 660 shots out of a total of over 1700 with visual effects. A team of over 1,500 artists created all of the X-Men digital doubles and provided them to other VFX vendors. The project was managed from Montreal, where filming took place, with asset creation, compositing and 2D work based in Bangalore, and key asset design from London.
Here is a look at their comprehensive work:
