No problem. Unfortunately, mp-2662 specifically is a structure that does not have this information yet, but to take another MnP example that does have this information:
from pymatgen import MPRester
mpr = MPRester(YOUR_API_KEY_HERE)
structure = mpr.get_structure_by_material_id('mp-999516')
print(structure)
magmoms = structure.site_properties['magmom']
print(magmoms)
This will output:
Full Formula (Mn2 P2)
Reduced Formula: MnP
abc : 3.339203 3.339494 5.369199
angles: 90.000000 90.000000 119.997123
Sites (4)
# SP a b c magmom
--- ---- -------- ------- ---- --------
0 Mn 0 0 0.5 1.981
1 Mn 0 0 0 1.982
2 P 0.333305 0.66661 0.25 -0.082
3 P 0.666695 0.33339 0.75 -0.082
[1.981, 1.982, -0.082, -0.082]
(In general, it is the older materials on the Materials Project that do not yet have site-projected magnetic moments. All newer materials should have them.)