As a stopgap to relacing the wheel with thinner spokes, which may not be so easy ,,,, take a good spoke out of the wheel. Run over to a bike shop that works on ebikes. If they are nice guys, they can measure it and order a dozen spokes for you.
If they laugh you off, then measure it yourself and order a dozen or more off ebay or a spoke shop like prowheelbuilder.com. Order the nipples too.
12G is 2.6mm diameter. 13G is 2.3mm diameter and 14G is 2 mm diameter,
L3 can be off by +/-1 mm and still work fine with double wall rims.
Thick spokes not so good on bike rims, better for motorcycles, but if you keep them snug, they'll last,