This Laowa-made lens sports a Nikon Z mount. If you want to use a filter on the lens, then the filter size is 67 mm.
From Photospecialist
Laowa 90mm f/2.8 2X Ultra-Macro APO Lens Nikon Z
WEX Photo Video
Laowa 90mm f2.8 2x Ultra Macro APO Lens for Nikon Z