const tbox = require('@turf/bbox');
const arctic = require('./arctic.json');
const bbox = tbox.default(arctic);
const sq = require('@turf/square-grid');
const cellSide = 40;
console.log(JSON.stringify(sq.default(bbox, cellSide, {units: 'kilometers'})));
I generated a bbox from these polygons:

this is my code:
turf-bbox gives me this: